WILEY ENGINEERING SERIES
LIEUT. LORN CAMPBELL, JR., U.S.A.
ncer in Charge of Welding Instruction,
Ordnance Department, U.S. Army.
TOTAL ISSUE, FIVE THOUSAND
JOHN WILEY & SONS, Inc.
LONDON; CHAPMAN & HALL, LIMITED
Copyrighted in Great Britain
BRAUNWORTH & CO.
5/2O BOOK MANUFACTURERS
BROOKLYN, N. Y.
(1) THE oxy-acetylene method of welding and cutting
metals has of late been receiving considerable attention.
Its tremendous power of creating, repairing and destroying
the work of man has been but recently recognized in its
broadest sense, and the demand for operators, skilled in
the manipulation of this apparatus, which always has been
far in excess of the supply, now knows no limit. Many
authorities have set forth their views and theories upon
this subject, in America and also in foreign countries. These
have been published from time to time in many of the leading
periodicals and magazines, as well as in book form. It seems
the purpose of most of these works has been to advance
the operators who already have a smattering knowledge of
this art, or to present to the purchaser of apparatus a set
of operating instructions.
(2) It is singular indeed that a school manual, devoted
exclusively to the instruction of the beginner, which will
serve as an aid to the instructor as well as to the student,
has not yet been put forth. It cannot be said that there
is not a demand for such. Recently there seems to have
been a mushroom growth of welding classes. The majority
of the vocational schools, colleges, night schools, and auto-
mobile schools have all entered the instruction in oxy-
acetylene welding on their rolls and each is attempting to
instruct in an entirely different manner from the other.
There can be no question as to the expediency of affording
the educational institutions a systematic as well as a stand-
ardized method of instructing. But the books and articles
of the nature mentioned are not suited to this purpose,
and were not designed for it. A school-book is wanted;
something to be used in the classroom, to be employed as
a reference in the shop practice, to be studied for what it
contains, and to indicate further lines of research, where
such are required.
(3) To meet this demand, the present" Manual" has
been written to serve the instructor as well as the student.
In its preparation many books, both well-known and
obscure, have been examined and the methods of shop
instruction have been carefully studied by the author.
(4) It has been found that regardless of how fast the
ground may be covered in the lecture room, the average
student's power of assimilation is limited and considerable
time has been spent in determining this ratio and applying
it between the lecture subjects and shop work.
(5) It must be remembered that while the chapters com-
prising the theoretical part of this welding manual follow
in the order given, the actual shop practice, as previously
mentioned, is the most important.
(6) Kindly aid has been received from many sources.
Granjon & Rosemberg, Kautney, M. Keith Dunham, S. W.
Miller, Henry Cave, C. J. Nyquist, P. F. Willis, Ben K.
Smith, and others have embodied in their writings many
excellent ideas, which have assisted the author in bringing
out certain points advantageously. The following manu-
facturers are to be given credit for many of the illustrations:
The Oxweld Acetylene Co., Newark, N. J.
The United States Welding Co., Minneapolis, Minn.
The Bastian Blessing Co., Chicago, 111.
The Linde Air Products Co., New York City.
The General Welding & Equipment Co., Boston, Mass.
The Messer Manufacturing Co., Philadelphia, Pa.
The Alexander Milburn Co., Baltimore, Maryland.
The Torchweld Equipment Co., Chicago, I1L>
The Davis-Bournonville Co., Jersey City, N. J.
The K. G. Welding Co., New York City.
The Chicago Eye Shield Co., Chicago, 111.
The Commercial Acetylene Supply Co., New York City.
The Welding Engineer, Chicago, 111.
The Journal of Acetylene Welding, Chicago, 111.
NOTE. Lieut. Campbell offers his services without charge to anyone
interested in this method of welding and may be addressed care of JOHN-
WILEY & SONS, INC., Publishers, 432 Fourth Avenue, New York City.
WILEY ENGINEERING SERIES
THE Wiley Engineering Series will embrace books devoted
to single subjects. The object of the Series is to place in the
hands of the reader all the essential information regarding
the particular subject in which he may be interested.
Extraneous topics are excluded, and the contents of each
book are confined to the field indicated by its title.
It has been considered advisable to make these books
manuals of practice, rather than theoretical discussions of the
subjects treated. The theory is fully discussed in text-books,
hence the engineer who has previously mastered it there, is,
as a rule, more interested in the practice. The Wiley En-
gineering Series therefore will present the most approved
practice, with only such theoretical discussion as may be
necessary to elucidate such practice.
I. APPARATUS 19
IT. OPERATION 27
III. SHOP EQUIPMENT 39
IV. APPARATUS REPAIRS 44
V. PREHEATING AGENCIES 51
VI. PART ONE WELDING OF CAST IRON 58
PART Two WELDING OF CAST IRON 67
PART THREE WELDING OF CAST IRON 70
PART FOUR WELDING OF CAST IRON 75
VII. PART ONE STEEL WELDING 81
PART Two STEEL WELDING 87
PART THREE STEEL WELDING 92
PART FOUR STEEL WELDING . . 97
VIII. BRASS WELDING 106
IX. PART ONE ALUMINUM WELDING 109
PART Two ALUMINUM WELDING 113
PART THREE ALUMINUM WELDING 118
X. WELDING OF MALLEABLE IRON 120
XI. OXY-ACETYLENE CUTTING 125
XII. CARBON BURNING 135
GLOSSARY . 145
INDEX ' . . 167
Oxy-Acetylene Welding Manual
(i) WHEN choosing a life vocation, one generally views
the possibilities it has to offer and delves deeply into these,
previous to making a decision. It is therefore thought
advisable at this time to present the student with an idea
of what is meant by oxy-acetylene welding and cutting;
how it is applied; the possibilities and advantages attached
to such an art.
(2) Acetylene gas, when burned with a proper portion
of oxygen gas, produces an extremely hot flame, in fact,
the hottest flame known. Its temperature is over 6000
degrees Fahrenheit. With this flame it is possible to bring
any of the so-called commercial metals, namely: cast iron,
steel, copper, and aluminum, to a molten state and cause
a fusion of two pieces of like metals in such a manner that
the point of fusion will very closely approach the strength
of the metal fused. If more metal of like nature is added,
the union is made even stronger than the original. This
method is called oxy-acetylene welding and differs from
what the average layman considers welding in the black-
smith's forge, insomuch that there is no blow struck to
assist fusion in this process. And while the forge method
is limited to wrought iron and steel which is detachable
2V j i t *i JOXY4ACETYLENE WELDING MANUAL
and of restricted size and shape, the oxy-acetylene process
has, practically speaking, no such limitations. d
(3) Manufacturers in the metal- working world were
very slow to grasp the real significance of this important
process, until the operators began demonstrating some of
its possibilities. At the present time, however, there is
hardly a metal barrel or tank
manufacturer who has not
discarded the old method of
producing costly leaky, riv-
eted drums and containers,
for this modern fusing proc-
ess. The manufacturers of
fire-proof doors and windows,
cooking utensils, seamless pipe
and tubing, office furniture
and what not, are now vir-
tually dependent upon the
welding torch at every turn.
(4) As a repairing agent,
the welding torch has no
rival. Whether it is a cast-
ing of iron, steel, brass, or " "^r^
aluminum that has broken ; (Courtesy of the Oxwela Acetylene Co.)
a boiler or tank that has FlG - 2 ~ In Enameled Products for the
Kitchen the Weld is Fast Replacing
worn away in spots, or an -,-.... D . , c v
J ' the Riveting, Brazing, and Soldering
error on the part of en- of the Light Sheet Metal Seams,
gineer, foundryman or ma-
chinist, the part can generally be reclaimed and made
stronger than originally. To-day practically no manufac-
turing concern that is dependent upon metallic machinery
could think of being deprived of its oxy-acetylene apparatus,
once having learned its worth. In the not far distant past,
were a gear or some casting to break, it probably meant closing
4 OXY-ACETYLENE WELDING MANUAL
down the entire plant until a new part could be obtained,
which, whether the source of supply were near or at a long
distance, would mean costly delay. With oxy-acetylene
equipment and an efficient operator on hand, almost every
emergency is provided for.
(5) If an automobile owner breaks a frame, he does not
consider replacing it with a new one, as the labor alone for
(Courtesy of the Oxweld Acetylene Co.)
FIG. 3. Welding Broken Frame of 5-ton Automobile Truck.
stripping his machine and setting it up again, not to men-
tion the cost of the new frame and the time required for
this operation, is prohibitive. Rather, he has his car taken
to the nearest welder or his portable apparatus to the car
and the job is completed within thirty or forty minutes,
with the frame at the point of the break made stronger
than ever. Locomotive frames are handled in much the
same manner, only more time is required and perhaps extra
operators, but the important point to be brought out is
the fact that on many jobs no dismantling is required and
the repair is permanently and quickly executed.
(6) An interesting example of the true worth of welding
was brought to the attention of the public when the United
FIG. 4. Staff of Instructors at the Ordnance Welding School, U. S. A.
States entered the European War, and all the interned
German vessels, which had been greatly damaged by the
orders of their commanding officers, were restored to working
condition with the oxy-acetylene and electric welding process.
This was considered impossible by many engineers not fa-
miliar with the process, insomuch as they looked upon oxy-
acetylene welding as applicable only to small parts and
6 OXY-ACETYLENE WELDING MANUAL
here some of the sections which had been blown or struck
out of the cast cylinders, etc., weighed many hundreds of
pounds. In many instances the ribs of these same vessels
were cut most of their depth, but these were restored to
working order in a remarkably short time and the results
were more convincing than any words.
(7) Cutting with the oxy-acetylene process is just the
opposite from that of welding. The latter might be con-
sidered constructive and the former destructive. In the
case of welding, two parts are brought to a molten condition
along the line to be joined and both fused together. Whereas
in cutting, one piece of metal, when brought to a red
heat, is cut in two by an oxidizing flame. Cutting has not
the wide scope that welding has, for it can only be applied
successfully at the present day to wrought iron, rolled and
cast steel. While it is limited in its scope, the speed of
this process in severing large masses of metal is very spec-
tacular and appeals forcibly to the observer.
(8) Probably the world's first awakening to the real
meaning of oxy-acetylene cutting came when the U. S.
battleship " Maine," was being taken from Havana Harbor.
All the heavy armor plate and seemingly immovable wreck-
age was cut into small sections which could be handled
easily. This was all accomplished with the cutting torch,
which seems to eat its way through metal with the same
ease that a hot knife goes through butter.
(9) Before and since the time of the " Maine," the cutting
torch has been accomplishing wonderful feats. In every
scrap yard, old boilers and the like are being cut into fur-
nace size; speeding up the production in answer to the
world's cry for more metal. The wreckage on railroads and
buildings using steel reinforcements is being cleared in
hours, with the aid of the cutting torch, where it required
days by other methods. Most of the fire departments in
the larger cities now carry the cutting torch as part df their
equipment, and to it has been credited the saving of many
lives, by its timely cutting away of steel doors, bars or barriers
which prevented escape. Much of the plate in this country's
(Courtesy of the Oxweld Acetylene Co.)
FIG. 5. Fireman Cutting |-inch Steel Fire Door with Portable Apparatus.
shipbuilding yards is being cut to size right on the job, and
the function of this torch in cutting off risers measuring
from one to thirty-six inches in diameter in the foundry
seems only to be of secondary importance in comparison with
8 OXY-ACETYLENE WELDING MANUAL
some of its other uses. In order to transport some of tf
largest inland lake boats which were much too long to pai
through the locks, to the sea, they were cut in parts, tran
ported, and later welded together and placed in service.
(10) It is not only possible to keep a cutting torch bun
ing under water, but it can also be made to cut. Coi
tracting companies are cutting off their piling under wat<
and it has been known that in European ports cutting hi
(Courtesy of Itie Acetylene Journal Publishing Co.)
FIG. 6. Welders of the Signal Corps, U. S. Army, in Action.
been successfully accomplished at a depth of thirty feet
A special torch is employed by submarines to cut nets unde
(n) In reviewing the oxy-acetylene welding and cuttinj
process, we find that its growth is one of the most remarkabl
the world has ever witnessed. About 1907 saw its industria
birth and since that time it has advanced by leaps am
bounds, rivaling the automobile industry in its progress
despite the opposition and criticism levied at it by workers
of other trades and its careless and unskilled manipulation.
(12) It is quite impossible to present anything like a
(Courtesy of the Acetylene Journal Publishing Co.)
FIG. 6a. Welders of the Signal Corps, U. S. Army, in Action.
complete list of the applications of this process, but a few
of its general uses are here enumerated:
(A) Airplane Construction. Welding of frames, sockets,
water and gasoline tanks, water jackets and valve cages to
10 OXY-ACETYLENE WELDING MANUAL
cylinders, intake and exhaust manifolds and connections,
spark plug thimbles and the repair of aluminum crank
(B) Automobile Manufacture. Welding of steel and alu-
minum bodies, transmission and rear axle housings, crank-
shafts, cylinders, gears, manifolds, pinions, crank cases, valves,
(Courtesy of the Oxweld Acetylene Co )
FIG. 7. Welding a 2 -foot Length of New Shafting on the End of a Motor
Shaft 2 Inches in Diameter.
rims, mufflers, frames, fenders, wind-shield tubings, and
(C) Boiler Shops. Welding and building up worn spots
around hand-hold plates, repairing cracks and checked
portions of fire boxes, retipping flues, connections, etc.
(D) Brass and Copper. Welding kettles, vats, tanks,
stills, floats, cooking utensils, manifolds, water jackets,
electrical and chemical wares, etc.
(E) Commercial Welding. Reclamation service on all
kinds of metals, quick and permanent repairs on all broken
parts of machinery.
(F) Electric Railway. Welding air receivers on air-brake
systems, building up shafts, bonding the rails, motor housings,
(Courtesy of the Torchweld Equipment Co.)
FIG. 8. This is a Steel Tank, Made of f-inch Plate, which Measures 30 Feet
Long and 8 Feet in Diameter, Fused into One Piece by the Welding Torch.
worn boxes, reclaiming gears and broken trucks, steel trolley
(G) Forge Shop. Welding complicated parts which can
not be conveniently handled in the forge.
(H) Foundries. Welding up blowholes, porous spots, and
reclaiming castings in general. The cutting off of risers,
gates, and heads on steel castings.
OXY-ACETYLENE WELDING MANUAL
(I) Lead Burning. Lead pipe joints, storage battery
connections and repairs, lead linings in vats, etc.
(Courtesy of Ben K. Smith, U. S. Welding Co.}
FIG. 9. Locomotive Cylinder to be Welded in Place.
(J) Lumber Mills. Building up worn shafts, repairing
gears, chains, and broken parts.
(K) Machine Shops. Rectifying errors on part of ma-
chinists and engineers. A "putting-on" tool in every respect.
(L) Manufacturers. Welding spouts and handles on
cooking utensils, fire-proof doors arid window sashes, office
files and furniture, chains, etc.
(M) Mines. Repairing pipe lines, boilers, broken shafts,
gears, and building up worn parts on dippers, etc. The
cutting torch is used for clearing away wreckage in case of
(N) Pipe Work. Welding of water, gas, and oil, steam
(Courtesy of the Oxweld Acetylene Co.)
FIG. io. Steel Roll Top Desk all Joints and Seams Welded. An Excellent
Example of High-grade Welded Metal Furniture.
and air lines. High-pressure refrigeration systems are cut
and welded in place.
(0) Plate Welding. Tanks for oil, steam driers, digesters,
vats, chemical receivers, generators, etc.
(P) Power Plants. Welding of steam, air, and water-lines,
of pump castings, cylinders, pistons, worn or broken parts, etc.
(Q) Railroad Work. Reclaiming bolsters, couplings, slot-
14 OXY-ACETYLENE WELDING MANUAL
ting forged engine rods, building metal cars, repairing fire-
boxes, patching and replacing side sheets, flue welding, build-
ing up frogs and crossings, cutting off rails, mud rings, weld-
ing cracked cylinders, cross-heads, steam-chests, building
(Courtesy of the Oxweld Acetylene Co.)
FIG. ii. Office Chair. Welded at all Joints.
up worn spots on wheels, rims and pins, welding spokes
and locomotive frames, etc.
(R) Rolling Mills. Fabricating " open-hearth," water
jacket doors, cutting up "lost heats," scrap plates and bar
stock billets. General repairs of furnace equipment, hot
beds, rolls, gears, engines, plates, etc.
(S) Sheet Metal Manufacture of tubing, oil-storage
barrels, metallic furniture, range boilers, etc.
(T) Shipyards. Cutting off plates and irregular shapes
of steel, channels, special sections. Building up of worn
shocks, building and patching hulls, stringers and the reclama-
tion of propellers, posts and broken parts of machinery, etc.
(U) Structural Steel Cutting holes for rivets, gussets and
splice plates, and wrecking. Welding up misdrilled holes
(Courtesy of the British Oxygen Co.)
FIG. 12. Cutting Armor Plate by the Oxy-acetylene Process.
and machinist's errors. Cutting channels, I beams, and
other shapes for coping, splicing and fitting rails, welding
reinforcing rods for concrete work of any desired length
and structural parts where bolting and riveting is difficult
(V) Scrap Yards. Cutting up scrap boilers, tanks and
other large work to mill size, wrecking structural buildings,
and reducing to small size, reservoirs, tanks and boilers,
OXY-ACETYLENE WELDING MANUAL
which are housed in buildings to remove them without
damage to the structures.
(W) Tractor Industry. Cutting and welding frames,
track and wheel guards, water, gasoline, and oil tanks;
(Courtesy of the Davis- Bournonville Co.)
FIG. 13. Here is Illustrated an Oxy-acetylene Machine for Cutting Holes
in the Web of Rails, or in Structural Iron, of not more than f Inch in
Thickness. It can be Quickly Attached and Accurately Adjusted to
Pierce through the Iron Instantly, without any Previous Drilling, and
it will Cut Smooth Round Holes, from \ to 2 Inches in Diameter in from
30 to 60 Seconds. It is Particularly Adapted for Railroad Work, and
Enlarging or Cutting Holes in Building and Bridge Work.
welding up of blowholes, porous spots and misdrilled holes
in castings of all kinds.
(13) The foregoing, as previously stated, is but a partial
list of some of the applications of the oxy-acetylene welding
and cutting process to various industries. What has the
future In store for it? Almost daily, some new application
is found for it and at the present time experiments are under
way in boiler construction, the results of which are not dif-
ficult to foresee. Giant hulls of seagoing vessels are being
fused together by welding and the limits of this wonderful
process which is now practically in its infancy are difficult
(14) During the World War many manufacturers of
non-essentials shut down and others turned their entire
production over to the government, changing their machinery
and in most instances their entire plant. What, then, are
those who are operating machines and apparatus, produced
by these firms before the war, going to do for replacements?
There is but one answer, have their broken or worn out
(15) Oxy-acetylene operators have always numbered far
less than the demand, a point which was clearly brought
out by the government when its immense Army and Navy
were being formed. There were so few men familiar with
the oxy-acetylene process that it at once took measures to
establish its own schools where men could be trained, a
thing that the commercial world had been THINKING of
doing for some years. As the demand for operators con-
tinues to increase, it behooves a man, even though he
is not a metal worker, to think and apply himself, in order
that he may "carry on," to the best advantage when oppor-
(16) The methods of instruction herein set forth are
very simple and while differing in many respects from those
used by the trade, have been most successfully employed
in producing efficient operators. Certain principles are in-
stilled in the beginner and some of the exceptions which are
of minor importance are overlooked to avoid confusion.
Criticism is expected from those who have never engaged
18 OXY-ACETYLENE WELDING MANUAL
in instruction of this kind on a large scale. There are many
differences to be expected on account of this very fact, for
there are few who have gone further than the instruction
of very small classes where individual attention may be
(17) All history of the process, gas manufacture and the
like have been omitted in order to give greater detail to
the actual shop practice and to have the operator become
familiar with his apparatus and thereby operate it with all
due respect and intelligence.
(18) Oxy-acetylene welding cannot be learned by watching
others work, although observation may at times assist the
beginner. Actual torch practice, brain work and a power
of "I will," produce the most efficient operators. For those
who earnestly apply themselves to the instructions which
follow, there is every reason to believe that success will be
(19) WELDING apparatus in general consists of two regu-
lators equipped with pressure gauges, two lengths of hose,
and a welding torch. The regulators are attached to cyl-
inders of acetylene and oxygen and are used to reduce and
maintain a uniform pressure of these gases for use at the
torch. The gases at reduced pressure are conveyed to the
torch by the hoses. The regulators should each have a
high-pressure gauge to indicate the contents of the cylinder,
and also a line or working-pressure gauge to show the gas
pressure on each hose. When the gases reach the torch they
are there mixed and combustion takes place at the welding
tip, which is fitted to the torch. Such an apparatus is called
portable, on account of its movability. There are other
equipments wherein one or both of the gases are generated,
but these will not be discussed here.
(20) For convenience oxy-acetylene welding apparatus
may be divided into three classes, depending upon the prin-
ciples used in securing the fuel gas or acetylene for the flame.
Low-pressure, medium-pressure and high-pressure apparatus
generally use about the same pressure of oxygen and it will
be called a constant. The acetylene gas is a variable and
in the low-pressure type only enough pressure is required
to overcome the friction of the line until it reaches the oxy-
gen injector, located in the torch, which acts as a syphon,
drawing the acetylene gas to the point of ignition. In a
medium-pressure type about three-fourths as much pressure
OXY-ACETYLENE WELDING MANUAL
is required on the acetylene line as on the oxygen. This
type is apt to verge on the injector type, as it depends to
some extent upon the oxygen under pressure carrying acety-
FIG. 14. A Portable Welding Unit.
lene gas to the point of ignition. In the high-pressure type
equal pressure on each line is used. To further make this
classification clear, a certain sized tip using, perhaps, 12
pounds of oxygen pressure can be used as an example. In
a low-pressure type perhaps 2 pounds pressure or less will
be needed on the acetylene line. On the medium-pressure
approximately 9 pounds will be required, while on the
high-pressure an equal amount, or 12 pounds will be needed.
(21) The mixing chambers for the gases may be located
in the head; in the middle of the torch, or in the handle.
By mixing chambers reference is made to that portion of the
torch where the two gases are brought together and mixed.
As can be seen with three different types of welding torches
FIG. 15. Location of Mixing Chambers in Welding Torches.
(i) Shows gases mixing in the handle. (2) Has the mixing chamber in the middle of the
torch. (3) Illustrates how the gases are kept separate until the head of the torch is reached.
Ox. represents oxygen gas; Ac. acetylene gas; and m mixing chamber.
and three different locations for the mixing of the gases,
the manufacturers can find a large range for producing
oxy-acetylene apparatus. Some undoubtedly will fill cer-
tain requirements better than others. Much, too,' will de-
pend upon the ability of the operator in handling a torch.
(22) Flashbacks are caused by the improper mixture of
the gases, which increases the rate of flame propagation to
such an extent that the flame will flash back to the mixing
chamber. Acetylene in a pure state will burn very much
slower than when mixed with equal parts of oxygen. When
22 OXY-ACETYLENE WELDING MANUAL
more oxygen is introduced the flame propagation is much
greater, so that when an excess of oxygen is used, there
is bound to be considerable trouble from backflashing. When
sufficient acetylene is introduced to the mixing chamber,
there is absolutely no chance for this lean mixture to occur.
If the flame flashes back to the mixing chamber, both gases
should be closed off immediately, at the torch, the oxygen
first, and then the acetylene gas.
(23) In some torches the heating of the mixing chamber
will cause a flashback and with these it is necessary to shut
off the acetylene and leave the oxygen valvs just cracked
and immerse the torch head in water, dipping it slowly,
so as not to cause too great a strain. The oxygen will bubble
out and prevent the water backing up in the tip. If the
flashback deposits enough soot on the inside of the tip and
the head to impair the working quality of the torch, the
soot should be removed by using a soft wire, preferably of
copper, or some other material which will not mar the tip.
(24) It is interesting to note the action of a regulator,
used to reduce the cylinder pressure on both gases. The
gas from the cy Under, at high pressure, comes directly into
the body of the regulator or chamber (4), Fig. 16, through
a fine nozzle (B). A seat of gallilith, casenite, or fiber
(C), attached to an arm (D), presses against this nozzle.
Arm (D), in turn, is attached to a very sensitive diaphragm
(E) and is moved every time there is a pressure exerted on
the latter. The movement of this diaphragm is controlled
by a handle or a screw, with a " cross-bar" attached to
its end as is shown at (F). This screw bears upon the dia-
phragm through the medium of the springs (G). As this
screw is forced inward the springs force the diaphragm in,
and thereby move the seat away from the nozzle of the
regulator. The gas, entering under high pressure, exerts
an equal force on all parts of the chamber and the diaphragm
receives its share. Now the, chamber walls are made of
a solid material, usually a bronze or brass, and cannot be
changed, but this diaphragm can be moved and as this
pressure is increased, the diaphragm is forced out and the
nozzle (B) is automatically closed by having the seat (C)
brought in contact with it. When gas is drawn off through
the line (H), the pressure within the chamber will naturally
FIG. 1 6. Cross-section of Regulator.
A, chamber; B, nozzle; C, seat; D, seat arm; E, diaphragm; F, cross-bar, or adjusting
screw; C, diaphragm springs; H, gas outlet; /, gas inlet.
drop and as it does so, the springs will force the diaphragm
inward, permitting a replacement of the gas drawn off.
Although not noticeable, there is a continual movement of
this diaphragm whenever the gas is being used. It can be
readily seen that the amount of pressure within the regulator
can be accurately set by the tension of the spring against
the diaphragm which is controlled by the screw carrying
24 OXY-ACETYLENE WELDING MANUAL
(25) There are two types of regulators manufactured for
the reduction of gases under high pressure, depending upon
the nature of work to be done. The high-pressure regulator
is employed for heavy work where a great deal of gas is
used and the regulator must pass it without much effort,
to prevent its freezing. This type of regulator is used on
cutting or on large welding work. It differs from the low-
pressure or ordinary type in four distinct features. Generally
it contains a much heavier diaphragm which is smaller in
diameter, making it stiffer in every respect. The tension
springs which act upon this diaphragm are much heavier.
The nozzle which presses against the seat is much larger,
to permit the passage of a greater amount of gas. Then, too,
a larger working pressure gauge must be used, in order to
read this high pressure. In the welding of metals, especially
in steel, the adjustment of the flame is a very important
matter, and absolutely dependable regulation must be had.
This is not possible with a high-pressure regulator and is
not intended to be so. The larger the diaphragm, the more
sensitive the regulator, and this point should be borne in
mind, and no small welding work attempted with the high-
pressure regulator. The reverse form of reasoning may
be applied to low-pressure regulators which have been used
in cutting. They are very likely to be strained and satis-
factory results cannot be expected, for they are not made
for that purpose. Acetylene regulators are constructed much
more sensitively than the oxygen regulators, to take care
of the lower pressure of gas and in a sense might be 'called
weaker, insomuch that the larger nozzle which passes the
gas is closed or regulated by springs which are not nearly
as strong as in the oxygen regulator. For this reason acetylene
regulators cannot be interchanged with oxygen regulators
for they will not stand the pressure demanded in the first
place, and in the second place, were a small quantity of
acetylene gas left in the regulator and oxygen introduced,
an inflammable mixture would be formed which is not ad-
visable to have present, on account of its explosiveness.
In many instances oxygen regulators are put out with the
copper diaphragms, whereas another metal must be used
on the acetylene regulators, because acetylene gas attacks
copper and usually a German silver or rubber diaphragm
is used. On account of the lower pressures used in charging
the acetylene cylinders, lower pressure gauges are used
than on oxygen regulators.
(26) All tension should be removed from the diaphragm
springs by screwing out on the " cross-bar" (that is, to the
left), before admitting gas under pressure to the regulator
to avoid abusing the seat. If a matter of 1800 pounds
pressure were admitted suddenly into any regulator that
had the seat removed from the nozzle, there would be a
sudden exertion upon the diaphragm, which would draw the
regulator seat up very violently against the nozzle, and if
it did not crack the seat it would undoubtedly groove it
to such an extent that it would leak and a trouble known
as "creeping regulator" would result. If this occurs, good
work cannot be expected because the flame will not remain
steady, and it is therefore necessary to take steps to rectify
this abuse. If there is a welding company available, the
regulator should be sent to it for repairs, but if the operator
is in an isolated district when this occurs, and must have
some means of continuing work, it will be possible for him
to remove the seat by unscrewing the back of the regulator.
If the seat has become grooved, and he thinks that this
is the trouble, many times the seat can be turned over and
the machined surface on the other side used. If the seat
is cracked, however, about the quickest way of making an
emergency repair is to turn out a new seat from hard rubber
ir fiber on a lathe.
26 OXY-ACETYLENE WELDING MANUAL
(27) In acetylene cylinders an absorbent called acetone
is generally used, which gives up the gas as required. A
full cylinder can be used for some time without any noticeable
difference in the gauge reading, and then, as it nears the
empty point, the gauge reading will drop very perceptibly.
It is therefore impossible to depend upon a high-pressure
acetylene gauge as an index to the contents of the cylinder.
The only method known to correctly check the amount of
acetylene gas on hand is to weigh the cylinder. There are
14^ cubic feet of acetylene gas to the pound, and when the
net weight of the cylinder is given the contents can readily
be figured. A tag bearing the net weight or figures which
will permit its computation is generally found attached to
each acetylene cylinder. In the case of oxygen cylinders,
there being no absorbent used, the contents of the cylinder
is indicated on the high-pressure gauge. On the latest
type gauge the contents will be shown by cubic feet, by
pounds pressure and by atmospheric pressure, to facilitate
the computation of costs by the operator.
(28) Occasionally a needle valve on a torch will begin
to leak and it will be found necessary to grind it. Realizing
that oil and grease are not to be used where oxygen is in
evidence, the question is often brought up as to the proper
lubricant to be used in doing this kind of work. Glycerine
is used by most manufacturers, together with powdered
glass or flour emery. In doing work of this kind the finished
job is thoroughly washed with ether. Occasionally when
piping oxygen lines through the shop, a screwed coupling
will leak and there is a temptation to calk the same with
white lead, but this should never be done, rather use lead
oxide mixed with the glycerine for this purpose as it forms
a paste which sets very rapidly and forms a hard, tough
(29) IN oxy-acetylene welding there are two gases used,
as the name would indicate, namely, oxygen and acetylene.
The first is used to intensify the flame and can in nowise
be likened to the inflammable nature of the second. There
is a great deal of oxygen present in the air we breathe. It
is an odorless, tasteless, and colorless gas, as most of us are
aware. In the commercial world oxygen is manufactured
by the decomposition of water into its elements, oxygen
and hydrogen, by the electrolytic process or is taken from
the air by a reduction process and is stored in steel-drawn
cylinders. These cylinders are drawn out of one piece of
steel and are of considerable thickness throughout, having
absolutely no seams, welded or otherwise. There is no filler
nor absorbent used on the inside of these cylinders, as pure
oxygen under pressure is not considered dangerous. The
standardized sized oxygen cylinder is one which contains
200 cubic feet of gas fully charged. Oxygen is compressed
in these cylinders at a pressure of 1800 pounds, at normal
temperature, and this pressure does not vary to any great
extent with change in temperature (as shown by table on
page 29). There is attached to the tip of the steel cylinder,
or "bottle," as some workers call it, a double seating valve
which has one seat operate when the cylinder is closed,
and the other when the cylinder is wide open. A regulator
is attached to this valve when working.
OXY-ACETYLENE WELDING MANUAL
FIG. 17. Sectional View of
Oxygen Cylinder without
(Courtesy oj the Linde Air Products Co.)
FIG. 1 8. A Standard 2oo-foot Oxygen
(30) Acetylene is the fuel gas, and is one of the greatest
containers of heat known. Burning in a free state, its
carbon content is so rich that complete combustion is im-
TABLE SHOWING THE DIFFERENT PRESSURES OF OXYGEN
AT VARIOUS TEMPERATURES
J 59 6
possible, and stringy black particles will be noticed floating
through the air. In order to fully combust this gas, oxygen
is introduced under pressure and a temperature of over
OXY-ACETYLENE WELDING MANUAL
6000 degrees Fahrenheit is obtained. (Acetylene contains
about five times as many B. T. U.'s (British Thermal Units)
as hydrogen.) This gas, unlike oxygen, becomes very dan-
gerous when in a free state it is subjected to an excessive
FIG. 20. A Generator for Producing Acetylene under Pressure.
pressure. The slightest jar may cause its disintegration
and a violent explosion follows. On account of this
danger, acetylene is not stored in a free state; neither is it
subjected to very high pressures. Its cylinders are put
out by various manufacturers to comply with the laws and
regulations of the Interstate Commerce Commission. Some
of these cylinders have been welded, but the most modern
method is to make them of one piece of drawn steel They
are then filled with an absorbent of some kind to take up
the gas and prevent any portion of it being left in a free state.
Acetone is the popular absorbent, and is a liquid capable
of absorbing twenty-five times its own volume of acetylene
gas at normal pressure. The filling material varies with each
of the manufacturers, but charcoal, asbestos and mineral wool
are in very common use. Acetylene is obtained from calcium
carbide brought in contact with water, or vice versa, and
is compressed and then stored in the cylinders at a pressure
varying from 150 to 250 pounds. When fully charged
this pressure will vary almost directly with any change
of temperature. Acetylene cylinders for welding are avail-
able in 100, 200, 225, and 300 cubic foot sizes.
(31) In setting up apparatus for the first time, the regu-
lator containing the 3ooo-pound gauge is attached to the
taller of the cylinders, which holds the oxygen gas, and
the other regulator is fastened to the shorter cylinder. The
hoses, which should be cleared of all powder or scale on
their interior, are then added. The black hose should
connect the oxygen regulator to the torch valve, marked
"OX" and the red hose, the acetylene regulator to the
torch valve stamped "AC." In attaching regulators to
full cylinders the "cross-bar" on the regulator should
always be turned out, that is to the left, until it turns freely,
to insure all pressure being released from the diaphragm,
before the cylinder pressure is turned on. Another pre-
caution that should be observed is the "cracking" of the
cylinder valves, before attaching the regulator, in order
to blow out any dirt or foreign particles that may be lodged
there, otherwise they will be carried into the regulator seat,
32 OXY-ACETYLENE WELDING MANUAL
or lodged in some small passage, which will impair the
working of the apparatus. Then too, if no truck or clamping
device has been provided, both the oxygen and acetylene
cylinders should be securely clamped or wired together,
a rule which should be insisted upon at all times, whether in
a job shop, manufacturing concern, or training school, or
any place where top-heavy oxygen cylinders are being used.
No particular harm results if these cylinders are turned over,
which is very easily done on account of their rounded base,
if no regulator is attached, but very frequently regulators
are attached and the hose connecting the same to torch
is found in the operator's way. The slightest pull or tripping
on this hose will upset the cylinder, usually demolishing
the regulator and expensive gauges and at times causing
much confusion among the workmen, on account of the
loud hissing noise given off by the escaping gas. Always
secure the drums or the cylinders in a safe manner.
(32) In turning on the gas, the oxygen valve is opened
wide until seated and the acetylene valve is only partially
opened. Often the question is raised as to where the oper-
ator should stand, especially when dealing with high-pres-
sure oxygen. It is recommended that the operator should
stand at the side and towards the rear when performing this
operation, for sometimes an unreliable gauge may be at-
tached, which if bursting, would send the glass into the
(33) As soon as an operator has gas pressure in his regu-
lators, he begins wondering how much pressure should be
placed on his line, that is, the portion between the regulator
and the torch. Of course, this depends upon the size of
the tip, but the operator should have some means of approx-
imating this pressure without going to his manufacturer's
chart every time. A neutral flame, ' that is, theoretically
equal parts of oxygen and acetylene, is desired for welding.
Now in lighting, the flame should stand away from the
tip a slight distance, in torches other than the low-pressure
type, while in these there will only be a good full flame issue
from the tip. Enough oxygen must be in evidence to bring
this acetylene flame down to the neutral point. If not
enough pressure is used, this result cannot be obtained,
and of course, more pressure must be introduced. It is
better to have too much pressure than not enough on the
the line, for the operator may use his torch valve to again
regulate this pressure and is always sure of enough gas.
Theoretically, all adjustments should be made at the regu-
lator, but in practice this is very seldom carried out. The
accompanying cuts will illustrate the five conditions which
every welder should be familiar with, in the flame adjustment.
Fig. 21 shows the acetylene turned on full; no oxygen has
FIG. 21. Acetylene Flame Blowing away from Tip.
as yet been introduced. The flame has a yellow appearance
and is very rich in carbon, as can be seen by the soot given
off. In Fig. 22 we see the oxygen being turned on; the
FIG. 22. Addition of Oxygen to Acetylene Flame.
yellow flame (A) is gradually giving way to a white part
at (B). In this condition we say that a feather flame exists.
Fig. 23 shows slightly more oxygen pressure. In Fig. 24
we have the neutral flame, which can be readily recognized
on account of its bluish white color and well-defined out-
OXY-ACETYLENE WELDING MANUAL
line, appearing like the end of an unused piece of chalk,
only, of course, much smaller. In Fig. 25 can be seen an
excess or too much pressure of oxygen. It will be noticed
that the neutral flame assumes a more bluish color, is a
FIG. 23. More Oxygen Pressure Applied. Flame Contains Slight Excess of
Acetylene, and is Known as "Carbonizing."
little pointed, and a very noticeable hissing sound is in
evidence. This is what is called an oxidizing flame and will
be again referred to. Too much oxygen is used. Operators
who attempt to turn on the oxygen first and then light it,
FIG. 24. "Neutral" Flame. Correct Proportions of Oxygen and Acetylene
will find that it does not burn, and their efforts will be useless.
In picking up a torch for the first time, any operator can
turn on one valve and detect by the odor of the gas, whether
it is oxygen or the fuel gas, and can light it in accordance.
FIG. 25. "Oxidizing" Flame. Too much Oxygen Present.
Some operators, however, attempt to turn on a little of
each gas and light. This is not to be recommended, for
flashbacks may occur. When the welder accustoms himself
to turning on enough pressure to accommodate whatever
sized tip he may have, he will find that there is no great need
for paying attention to the pressure gauges on his regulators
except to check up on the full drums of oxygen, and to teli
whether he has enough gas left to complete a certain piece
(34) A neutral flame is theoretically composed of equal
parts of oxygen and acetylene ignited, but this ratio is very
seldom worked out in practice. There is usually an excess
of oxygen in evidence. A neutral flame is generally spoken
of as being over 6000 degrees Fahrenheit, and this does not
vary with the different sized. tips as most welders think.
Of course there are different quantities of heat between
a very small tip and a large sized one, but the temperature
of the flame is the same.
(35) If too much acetylene gas is used, a feather flame
such as was seen in Fig. 23 will appear. This has a car-
bonizing effect on the weld, for it introduces carbon and
causes the weld to become very brittle.
(36) If too much oxygen gas is used, the effect shown in
Fig. 25 will take place, and the weld will have oxygen intro-
duced, which is a very detrimental feature, and is particu-
larly noticeable in working on steel, for it raises a white
foam over the surface of the melted metal, which sometimes
is worked right into the weld itself/An experienced welder
will always know just what kind of a flame action he is
obtaining on his weld, not because he takes the flame away
every time he wishes to look at it, but he can tell by the
action of his metal exactly the nature of his flame.
(37) Infra-red (heat) and ultra-violet (light) rays present
to a small extent in the neutral flame are injurious to the
naked eye. Colored glasses or goggles are used to shield
the eyes when working with this flame. Too dark a glass
should not be used, as it will cause a strain upon the eyes
more injurious than the flame. Exposed metal frames should
be avoided too, as they hold the heat and burn the operator.
(38) To shut off the . apparatus for several hours or so,
OXY-ACETYLENE WELDING MANUAL
it is best to relieve all pressure from the lines, such as hose
and so forth, and to do this close both tank valves; open the
(Courtesy of the Chicago Eye Shield Co.)
FIG. 26. A Spectacle Made for Welders, having a Frame of Fiber and Arranged
so that Lenses may be Replaced.
(Courtesy of the Chicago Eye Shield Co.)
FIG. 27. Showing Cover Glass which Protects the Colored Lens and the
Replaceable Features of a Modern Goggle.
torch valves; release the tension on the regulator, by screw-
ing the " cross-bar" to the left, and finally, close the torch
valves. It is quite necessary that these torch valves closed,
for quite frequently, if a small tip is in the torch and
an excess of oxygen pressure comes through the line, when
both torch valves are open, much of the oxygen may back
up the acetylene line and cause a serious flashback when
lighting up. This can be avoided by keeping both torch
valves closed when not in use.
(39) If a valve on an empty acetylene cylinder is left
open the acetylene gas will escape, and mixing with the air,
which is a supporter of combustion, a very inflammable
mixture will be formed. If any fire is present, such as might
be smouldering in a forge, possibly not used for several
hours or so, or a match lighted, or a flame started in any
way, an explosion is likely to occur. When an acetylene
cylinder is exhausted, as far as possible, in a moderately
high atmospheric temperature, then shut off for a while
and the temperature drops, air will be drawn into the vacuum
thus formed when the valve is again opened. In this man-
ner an explosive mixture forms in an empty acetylene cylinder
and is certainly to be avoided. Care should be taken,
expecially in winter, to guard against such occurrences, as
in some outlying shops a decided change in temperature
takes place between closing time and starting up time the
following morning. Acetylene tanks should always be se-
curely closed when empty, not only -for the above reasons
but insomuch that each contains acetone, which is likely
to escape if the tank is thrown around. Acetone is very
costly and used extensively in the manufacture of smokeless
powder, so that at times it is hard to replenish.
(40) Oxygen has an affinity for oils and greases, and
should not be allowed to come in contact with them, especially
in confined places, as a spontaneous combustion may result.
Oils and greases should never be used around oxy-acetylene
welding apparatus and on nearly every apparatus on the
38 OXY-ACETYLENE WELDING MANUAL
market the words "Use no oil," will be found. Despite this
precaution, however, many times ignorant operators will
be found squirting oil into the holes around the regulator
cap, and through the gauges, in order, as they say, to allow
them to work easier. This use of oil should be discouraged,
and the sooner the better.
(41) IN equipping a shop for welding, in addition to the
welding apparatus, the operators are many times unde-
cided whether it is advisable to have a planed metal or a
brick top table to use for welding purposes; each has its
advantages, but were there a choice of one or the other,
it is suggested that the brick-top table be used. The theory
of having a planed metal top for lining up work does not
prove as satisfactory in actual practice as might be expected,
for the simple reason that the average welder generally
places his metal in direct contact with this cold top, and
much of the heat which is supposed to go into the weld is
conducted away by the table top, producing a hard, brittle
weld. In the case of cast iron, these welds are generally
porous. Then too, the operator to a large extent depends
upon the table top for lining up his work and does not study
his contraction and expansion as thoroughly as he might.
The result is that many of his pieces warp in cooling. To
rectify the first objection it is advisable to cover the table
top with asbestos paper as shown in Fig. 28. In the second
place, sometimes clamps are used to hold the work in position.
Preheating without a layer of bricks on a metal-topped
table is not to be recommended.
(42) A fire-brick table, made up along the lines shown
in Fig. 29, is very easily constructed and can be used for all
sorts of jobs. It is well to have everything clear around the
legs and have no braces to cut the operator on the shins
OXY-ACETYLENE WELDING MANUAL
or to interfere in any way with his work. The best fire
bricks obtainable should be used. A large number of extra
FIG. 28. Method of Holding Heat when Welding on Metal Top Tables.
Asbestos paper, P, is laid upon the metal top, M, and the pieces, A and B, placed upon P
in such a manner that the weld can be made at C. The asbestos paper prevents too much heat
escaping from the bottom of the weld.
bricks should always be on hand for they come in very
handy in most of the welding operations, and in fact to
FIG. 29. A Fire-brick Table for Welding.
Angle iron measuring 2 by 2 by \ inches is welded together in the manner shown and covered
with fire-bricks which measure 2 i by 45 by 9 inches.
conduct a welding shop without fire bricks could almost
be likened to a blacksmith's shop without an anvil. Be-
sides being used for table tops, preheating furnaces of a
temporary nature may be built and the bricks used to jack
up and align many jobs which could not be handled otherwise.
(43) An emery wheel plays a very important part in a
commercial welding shop, insomuch that rust, scale, and
unnecessary metal can be removed in a very short time
by its use. A flexible shaft attachment should be on hand,
FIG. 30. One Shop in which Instruction in Steel is being Given, at the
Ordnance Welding School.
Note the construction of the welding tables. Two or more may be placed together, to give
as large a surface as desired.
if possible, or a portable grinder of some kind, for in many
cases where the casting, or the piece being worked upon is
too heavy to bring to the emery wheel, the wheel can be
brought to it and many places ground down by its use that
would be impossible with a stationary grinder.
(44) Many times when working near a hole which may
be threaded, the welder has much difficulty in keeping his
42 OXY-ACETYLENE WELDING MANUAL
metal from entering the hole. At other times it is neces-
sary to back up preheated work such as aluminum, to
prevent its collapsing. Ordinary clay or putty cannot
be used for this purpose. The simple reason being that
when metal is heated it expands and the clay or putty in
giving off its moisture contracts, showing two opposite reac-
tions. Retort cement is a name given furnace cement
mixed with shredded asbestos, this, as well as carbon flour,
has been found to be very satisfactory for filling in holes
and backing up pre-heated work. Retort cement is purchased
in airtight containers, hardening very quickly when brought
in contact with the air, so at all times it should be kept in
containers similar to those in which it is purchased. It
cannot be reclaimed once it is hardened.
(45) A blacksmith forge will be the medium of saving
much valuable gas and time in a welding shop. It will heat
up parts to be welded in very short order and while in this
condition they may be welded and then thrown back into
the forge and allowed to cool very slowly.
(46) Several pails of water should always be located
where welding is being done to prevent fire from flying
sparks; to cool the torch tips and filler-rods, when working
on large jobs; to keep certain parts of work being welded
cool, and to harden or temper other parts. .
(47) A simple and efficient manner of handling flux in
the welding shop has puzzled many welders, on account
of the flux containers being easily upset, their inaccesibility
and the action of the air upon large quantities of flux. A
simple method of overcoming this is to cut in two, a two
and one-half or three-inch pipe coupling and mount it by
welding on a square piece of one-eighth inch plate, as shown in
Fig. 31. This type of container is very hard to upset*
may be used when working on preheated jobs; is easy to get
at on account of its shallow nature, and, as it only holds a
small amount of flux, it can be cleaned out frequently and
a fresh flux will always be available.
(48) Additional equipment beneficial to the welder will
be a quantity of various sized carbon rods and blocks; as-
bestos paper; goggles; V-blocks for lining up shafts and
an assortment of mechanics' tools, such as wrenches, ham-
mers, chisels, hack-saws, and other things which might be
used in dissembling or assembling various kinds of machinery.
(49) Another important item which is generally overlooked
in the average welding shop is the question of ventilation.
Although the welding flame itself contains no objectionable
FIG. 31. A Good Flux Container for the Welding Table.
gases, those from fresh charcoal preheating fires, those given
off when some of the alloys of the filler-rods are melted
when brass, copper, and other metals are being worked on,
and from gas engine exhausts are not desirable. At times
they will give the operators violent headaches unless means
are taken to carry them off. The ventilation should be such
that it will not directly affect the work. Drafts are to
be avoided as much as possible, for many times they will
warp pieces being preheated if allowed to come in direct
contact with them. It is a good thing to remember that
indirect ventilation and plenty of it is a prime requisite
in a good welding shop.
(50) OCCASIONALLY in setting up a welding apparatus, a
leak may be noticed along the lines, some time after the
plant is in operation. Leaks on either the oxygen or acet-
ylene lines are to be considered dangerous as well as costly
and therefore to be avoided at all times. When the cylinder
valves are closed on the drums containing the gases, and the
hands on the low-pressure gauges of each regulator are
seen to drop or reduce their pressure when the torch valves
are shut off and allowed to remain so, this is an indication
that there is a leak between the regulator and the torch.
It is not desirable to use a match or a flame of any kind
in testing for leaks. There are various methods employed
by the cautious welder, but about the best of these is a soapy
solution of water, which is kept in a can at all times and
is applied with a paint brush. If this solution is applied to
any leaky part, bubbles will form immediately and the
leak will bt located.
(51) At times, when working in isolated places, where
repairs cannot be had, and no means have previously
presented themselves for testing out the cylinders or the
apparatus as a- whole, it may be found that the threads or
ground seat on the cylinder valve of the regulator which
is connected will be in such a condition that a leak is in evi-
dence. Or it may be that the threads will not permit the
seat being drawn up sufficiently to make it airtight. In
cases of this kind, the welder must find some means of pro-
APPARATUS REPAIRS 45
ceeding with his work, and while it will be impossible for
him to use white lead or any oily substance with safety,
he may stop the leak with litharge or lead oxide mixed with
a small quantity of glycerine. A string soaked in this solution
may be wound around the main connection and the swivel
nut screwed up to the seat as far as it will go. If allowed
to harden for a short time, the litharge will set and a very
satisfactory temporary repair will be effected.
(52) The method shown in Fig. 32 of attaching con-
nections to hoses so that they will not blow off when pres-
sure is applied is a very simple and effective means of over-
coming this difficulty. Undoubtedly it will assist some
operators in solving the trouble that has been occasioned by
FIG. 32. Method of Attaching Hose to Connection so it cannot Pull or Blow off.
the ordinary hose clamps, especially when doing cutting or
heavy welding work where the gas pressure is considerably
higher than usual. The wire used should be large enough to
prevent cutting the fabric in the hose.
(53) An injured hose which may leak should never be
used after the leak is noticed unless some means are taken
to repair it. The use of tape in trying to repair hose on
an oxy-acetylene welding outfit should never be permitted.
The most efficient way of overcoming an injury of this kind
is to cut the hose at this part and insert a piece of pipe.
The ends of the hose are then wired to this pipe and a union
is thereby effected which will generally outlast the life of
the hose. Special connections for this purpose are put out
by most welding companies, so that a supply may be on
hand if hose trouble is expected.
46 OXY-ACETYLENE WELDING MANUAL
(54) When transporting welding apparatus, occasionally
the " cross-bar" on the regulator is lost and many times the
operators do not know what is to be done. The purpose
of the " cross-bar," as we have already seen, is only to apply
pressure on the diaphragm springs, so that if a set screw
of the same diameter and same thread as those of the " cross-
bar" can be found and screwed into its place with a wrench,
a section of filler-rod can be welded across the top of it and
the use of the regulator will not be impaired. If a special
thread is used by any particular company, a piece of brass
or iron can be turned down in a lathe to fit.
(55) The manufacturers of practically all regulators use
the quarter-inch tapered pipe thread in attaching the cylinder
connections to the regulator and do not depend upon the
threads being gas-tight, so they solder them in. There are
various types of cylinder connections put out by different
manufacturers of the gases and occasionally it may be neces-
sary to use a cylinder of gas which contains a different con-
nection than is supplied on the regulator. Various adapters,
such as shown in Fig. 33, are supplied to overcome this
difficulty, but at times the operator is confronted with the
very embarrassing situation, of having a cylinder of gas
and his regulator of different connections, but no adapter
suitable. This predicament is usually found when some
very important work is to be done and sometimes far from
a supply depot. At times the operator may have an adapter
which will fit the cylinder but not the regulator. If this is
the case, his difficulty can be very easily overcome, for gen-
erally all adapters are made of two parts, " sweated" to-
gether, and have the same quarter- inch tapered thread as
used in the cylinder connections on the regulator. The adapter
can be separated, the tank connection removed and the
correct connection " sweated" into the regulator.
(56) Most gauges used in the oxy-acetylene industry to
APPARATUS REPAIRS 47
indicate gas pressure are of the Bourbon type. The most
recent types of the oxygen high-pressure gauges are con-
structed with a hinged back and a solid front, which means
that should an oil or foreign matter enter the gauge from
(Courtesy of the Bastian- Blessing Co.)
FIG. 33. Various Types of Adaptors Used to Connect Regulators to Cyl-
inders having Different Connection.
any source whatsoever and tend to burst it, the back would
be blown off and there would be no glass that could possibly
fly around. This is a safety device which has been welcomed
with much enthusiasm on the part of the oxy-acetylene in-
OXY-ACETYLENE WELDING MANUAL
dustry. When leaks occur in gauges, it is always best to
remove the guage from the regulator, stopping the hole
temporarily with a pipe plug and return the gauge to the
manufacturers for repair. These gauges are very delicately
constructed and can be rendered useless if handled by the
(Courtesy of the U. S. Gauge Co.)
FIG, 34. Showing Solid-front and Hinged-back Features of a "Safety-first"
High-pressure Oxygen Gauge.
inexperienced. A great many times after the case of the
gauge has been jarred or loosened, the screws connecting
this case to the inside working mechanism are tightened up,
breaking the soldered connection holding the spring tube
on the inside of the gauge. This causes a leak which can
be repaired quite easily if the operator is able to solder it.
It must be remembered, however, that if the flame is brought
in contact with any of the springs that their tension will be
lost and that the gauge may not operate correctlv after this
repair is made unless great care is exercised.
(57) Undoubtedly there are many welders who in begin-
ning to operate their welding apparatus conclude that their
FIG. 35. A 3ooo-pound High-pressure Oxygen Gauge.
gauges must be at fault when they show a reading after
apparently all pressure has been released in closing down the
apparatus. It is to avoid the impression that the gauge
is at fault that time is here taken to show that even though
the cylinder valve is closed and the " cross-bar " on the regu-
lator screwed out that when the torch valves are opened to
drain the lines there will still be a reading on the high-pressure
50 OXY-ACETYLENE WELDING MANUAL
gauge if the regulator seat is in good working order. It is
simply a case of gas being trapped between the regulator
and the cylinder valve. To reduce this reading it is only
necessary to screw in the " cross-bar," thus opening the
regulator seat. This could be avoided if the cylinder valve
were closed first and the torch valves opened while the regu-
lator " cross-bar " were still screwed in, then as soon as the
gas had left the line, the torch valves could be closed and
the " cross-bar " on the regulator could be screwed out
(58) PREHEATING, as applied to oxy-acetylene welding,
means the application of heat to the article to be welded
(Courtesy of the Messer Mfg. Co.)
FIG. 36. A Large Job Prepared for Welding.
in some manner which is usually different than by the
welding flame itself. Charcoal, coke, kerosene, crude oil,
coal and natural gas are used for this purpose. The prin-
cipal reasons for pre-heating parts to be welded are: To
take care of the effects of contraction and expansion on the
confined ends; to save time, gas, and material; and to make
52 OXY-ACETYLENE WELDING MANUAL
a better weld by making it quicker and with less chance of
burning up the metal.
(59) On account of the ductile qualities of steel, there
is not quite as much heat used in preheating, to take care
of the contraction and expansion, as in cast iron. On brass
work a very dull red heat is considered sufficient, or other-
wise the alloys might burn out. When preheating aluminum,
(Courtesy oj the Messer Mfg. Co.)
FIG. 37. Showing how Large Work can be Covered with Asbestos Paper
there will be no change in color as the heat is introduced,
so other methods are used to determine the correct tem-
perature. Three methods are used for this purpose by most
welders. " Half-and-half " soldering wire will usually
melt when applied to the surface of aluminum which is
preheated to the proper state; the puddle stick when drawn
smartly across the heated surface should scrape off the
oxide and leave a clear blue streak if the work is in condition
PREHEATING AGENCIES 53
to be welded; and if a medium-sized tip is brought down so
that the neutral flame just touches the surface for a second
or two, the metal will sweat, if at the proper temperature,
and small globules which have the appearance of mercury
will stand out on the surface.
(60) The beginner must study contraction and expansion
in order that he may know when and where to apply it in
figuring out his work. Many welding jobs have turned
out to be failures through lack of knowledge in this respect.
Take, for example, a water-cooled cylinder block of the ordi-
nary gas engine; the water-jacket may be broken when the
water is allowed to freeze in it. This problem has certainly
confined ends, but some welders have attempted to weld such
jobs cold, that is, without preheating, and possibly have
succeeded in executing what they thought was a very fine
weld, but upon examination, have discovered that the cylinder
walls, which are very accurately machined, have been warped
to such an extent that the block is rendered useless. This
is strictly a " preheating " job, and the cylinder should be
brought to a dull red heat if the best results are to follow.
As has been stated elsewhere in this volume, the weld
should not be considered successful unless the piece worked
upon can be returned to a usable state.
(61) Several different fuels have been mentioned, all
of which can be used for preheating purposes. Charcoal
is considered the best agent for general welding, as it gives off
a very steady heat which will gradually be absorbed by the
article worked upon, bringing it to the heat desired and hold-
ing it there throughout the welding operation. It will then
permit very gradual cooling, as this sort of fire takes a long
time in dying a desirable asset in work of this kind. On
account of the scarcity of charcoal and its high price, other
agencies are used and chief among them are torches using
kerosene, crude oil, or city gas, as a fuel. These usually
OXY-ACETYLENE WELDING MANUAL
heat up the work more quickly, but care in their manipula-
tion is necessary. A preheating torch to be used in con-
junction with city gas can be very easily constructed, if the
details of Fig. 38 are observed. This proves to be a very
efficient and cheaply constructed apparatus.
FIG. 38. Preheating Torch, Constructed of Black Iron Pipe, for Burning
(62) When work is being preheated, it is best to have
it protected from all drafts, to prevent warping. Possibly
the most extensively used material for building up temporary
ovens to hold the heat and protect the work from the air
currents is fire brick and with it asbestos paper. When
FIG. 39. Temporary Preheating Oven, Built of Fire Brick.
setting up an ordinary casting for preheating, these bricks
are built up in builder's fashion, about four inches away from
the piece itself, as shown in Fig. 39, and practically level
with the top of the piece. If charcoal is to be used, draft
spaces are left in the first row of bricks as shown, and the
charcoal ignited through the openings with the welding
torch. The work to be welded should have the line of weld
at the top if possible and be set up from the floor, or the sur-
PREHEATING AGENCIES 55
face upon which the oven is resting, on one or two fire bricks,
in order that the full benefit of the heat will be received.
Asbestos paper is then laid across the top, and the oven will
appear as in Fig. 40. When starting the fire, a layer of
charcoal, a matter of two or three inches thick, is at first
used, but as the chill is taken off the piece the oven can be
filled to the top, and usually this is enough to complete the
(63) In order to protect the operator, when working over
hot fires, it is recommended that the asbestos covering be
left on, and that only a small section immediately in the
FIG. 40. Temporary Preheating Oven of Fire Bricks Covered with Asbestos
vicinity of the weld be removed, which can be accomplished
by cutting a " U " in the paper as shown by the dotted lines
in Fig. 40. This can be turned back, exposing the place
which is to be welded, and at the same time protecting the
operator, to a large extent, from the unnecessary heat.
When the weld is finished, this lap can be turned back and
the piece allowed to cool. On pieces which require turning
and must be welded in several different positions, the pre-
heating oven, as it is called, should be built considerably
larger, to provide for handling the work. , It must be remem-
bered that during the entire operation, the piece should be
left inside the oven and should not be removed to a welding
OXY-ACETYLENE WELDING MANUAL
table. Some beginners make the mistake of doing this.
When welding with the charcoal in closed rooms, during the
winter months, the fumes will be found to be very disagree-
able and means should be taken to provide indirect ventila-
tion, otherwise the welders will be troubled with headaches
and smarting eyes.
(64) When using preheating torches, the ovens are built
much closer to the work and do not have the openings along
the bottom row of bricks. They are made as tight as possible,
and in some cases it will be found advisable to build up the
walls with two layers of bricks, with asbestos paper between
FIG. 41. Showing How Oven is Built when Preheating Torch is to be Used.
Torch is Showi.. at (A).
them, in order to hold the heat and cause the work to heat
up in a more uniform manner. A hole is left in one end of
the oven, through which the flame of the preheating torch
is introduced as shown in Fig. 41. It is not thought best
to have the torch flame come in direct contact with the work
which is being preheated, and a baffling plate of metal or
brick is placed directly in front of the flame, in order to
spread it around the oven. Judgment will have to be used
in all such work.
(65) The setting up of the work, when preheating, is an
important point overlooked by many welders, especially so
in the case of aluminum. Care should be taken to see that the
PREHEATING AGENCIES 57
work has a good solid setting and is braced at a sufficient
number of points, to prevent its sagging when in a pre-
heated condition. Many times when working on rough sur-
faces, a few firebricks distributed around the bottom of the
oven with a dab of putty, clay, or retort cement, placed upon
them, will form an excellent cushion upon which the work
can rest and the operator may feel confident that no sagging
PART ONE. WELDING OF CAST IRON
(66) IN order to know how to weld, it is quite imperative
that the operator first know the kind of metal he is to work
on. It is surprising to find how few welders know their
metals thoroughly. An incident might be cited where some
welders depend upon the sparks given off by the emery
wheel in determining the kind of metal they are about to
weld. They will approach the wheel; grind off their work,
noting the sparks; return to their welding table; choose their
filler- rods and do their welding without any delay whatso-
ever, much to the consternation of their fellow workers.
There are four simple ways in common use to distinguish
between cast iron, malleable iron, and steel; they are: By
the cross-section of a fresh break, by application of the weld-
ing torch, by the sparks given off when applied to the emery
wheel and by the chisel test.
(67) Externally cast iron usually has some sand on its
surface and its cross-section shows the grain to t>e fine, even,
and to have a dull grayish color. The surface of malleable
iron contains no sand and its grain is very fine, such as cast
iron, but slightly darker in color. A very fine steel veneer
is on all surfaces of malleable iron, which is much lighter
in color. When the welding torch is applied to cast iron,
no sparks are given off, but when applied to malleable iron a
bright spark is thrown off which breaks in falling, showing
that the outside material is steel. These sparks soon cease
and the metal which is molten is covered by a heavy oxide
WELDING OF CAST IRON
or skin which recedes or draws away from the flame slightly,
showing a very porous cast-iron interior. When brought in
FIG. 42. Characteristic Sparks of Different Irons and Steels Thrown off
by an Emery Wheel. Wheel should be Clean Cutting and Run about
7000 Feet per Minute.
(1) Shows cast iron. No sparks unless impurities arc present.
(2) Is wrought iron almost free from carbon. Heated particles thrown from wheel follow
straight line. These become broader and more luminous some distance from their source of heat.
(3) Illustrates mild steel action. Small amount of carbon present causes a division or forking
of the luminous streak.
(4) Shows the effect of increasing the carbon from 0.50 to 0.85 per cent in mild steel. The
iron spark lines diminish: the forking of the luminous Ftreak occurs more frequently, being
subdivided by re-explosions from smaller particles.
(5) Is a piece of carbon tool steel. The iron lines are practically eliminated with the increase
of the explosions and subdivisions, causing display of figures.
(6) Gives the spark of high-speed steel, containing in addition to 65 per cent carbon, other
alloying elements, chiefly tungsten and chromium.
(7) Represents a manganese spark. (Occasionally found in cast iron.)
(8) Shows spark thrown from old grade of "Mushett" steel.
(9) Represents a magnet steel spark.
contact with the emery wheel steel sparks, which are very
luminous and break in falling, are given off first in the case of
malleable iron, but they soon change to the dull red spark
OXY-ACETYLENE WELDING MANUAL
of cast iron. When a chisel is applied to cast iron, the iron
chips off; when applied to malleable iron the edge will curl
up, then chip off when the cast iron is reached. The cross-
section of cast steel shows a bright, coarse, silvery gray
METHODS OF DISTINGUISHING METALS
Here are five methods, any one or all of which may be used to learn the
nature of common castings which might confuse the welder.
Generally smooth and
free from all sand,
weighs about same
as cast iron.
with sand in evi-
than cast iron.
smooth but gen-
Ring of bright steel
with darker iron
dark gray, crys-
Few steel sparks and
then iron sparks
break in falling.
Dull red sparks
that do not
Surface will curl and
interior break off.
Will curl before
Will chip off.
Gives way before
flame and delivers
few sparks. Metal
Gives forth bright
break in falling.
Gives no sparks
there are im-
grain. When the torch is applied a distinctively steel spark
which is luminous and breaks in falling is thrown off. When
applied to the emery wheel steel sparks are thrown off; when
the edge is chipped by a chisel it will curl up.
WELDING OF CAST IRON 61
(68) The metal in the filler-rod should be the same in
practically all cases as the metal to be welded. There are
few exceptions to this rule, but the principal one is that of
malleable iron. The cast iron in the rods is of a very good
grade and generally much better than the piece to be worked
upon. To permit the ready flow of the rod and eliminate
oxidation, as much as possible, three per cent of silica is gen-
erally used in the casting of filler-rods for cast iron welding.
Piston rings and other scrap iron should not be used for filler-
rods, as they contain many impurities s'uch as core-sand,
dirt, grease, etc., which will ruin the weld. It is dishearten-
ing to see some operators attempt to economize on the filler-
rod. It is not an uncommon sight to see several dollars' worth
of gas and the same amount of the welder's time, together
with a few cents' worth of filler rods all lost, and the opera-
tor's reputation ruined. This, because an attempt is
made to save the few cents involved in the filler-rods by
substituting a rod of a very poor grade.
(69) A flux is not used, as many suppose, to cement the
filler-rod to the metal. It is used purely as a cleansing
agent and may be likened to the acid used in soldering.
It does not act on the metal until the latter has reached the
melting-point, but then it starts to break up the oxides and
clean the surface. This action permits the metal to flow
together more readily. A cast-iron flux is always used in
welding cast iron, to break up the oxide, because the cast
iron itself will melt before the oxide and no matter how hot
the metal is it will not flow together as long as this oxide is
(70) To obtain the best results, reliable fluxes should
always be used. Occasionally an accident will happen to
the flux can, when the operator is on some isolated job and a
substitute flux must be obtained at once. Equal parts of
bicarbonate of soda (cooking soda), and carbonate of soda
OXY-ACETYLENE WELDING MANUAL
(ordinary washing soda), may be purchased from any grocery
in the powdered form and mixed together thoroughly. This
will tide the welder over until he can return to the shop and
replenish his supply.
(71) The flux is generally applied by means of the filler-
rod. One end is heated and dipped in the flux; enough will
adhere to break up part of the oxides, on the ordinary-sized
job. The flux is carried to the work, which should be at the
melting-point and introduced between the flame and the metal.
Oxides will break up immediately and the metal will flow
together, but it must be remembered that the flux has no
FIG. 44. Whenever Possible, the Beginner should "V" His Work, and Com-
plete His Weld from One Side only. On heavy work, however, it will
be necessary to " V" out from both sides, as is here shown.
action on cold or moderately heated metals. The flux as
has been explained is used to clean the metal and break up
the oxides. To the oft-repeated question, how often should
the flux be applied, answer is made as follows: As often as
it is necessary to clean up the metal and break up the oxides.
All fluxes should be kept in airtight containers when not in
use, to keep their chemical contents in the very best condi-
tion and it is best to use only a small quantity of flux on the
welding table at one time.
(72) Oxy-acetylene welding is purely a fusing process
and the most important points to remember in executing
a weld are, to eliminate the entire crack in the fracture and
WELDING OF CAST IRON 63
to add the filler-rod without changing the character of the
metal. On thin pieces of metal it is possible to depend upon
the force of the flame to entirely penetrate to the depth of the
crack but on work three-eighths of an inch thick or over, it
is well to " V " out or remove some of the surface metal around
the crack in order to get down to the bottom. By " V-ing "
we mean to chip or grind off each edge at an angle of
approximately 45 degrees, so that the opening will form an
angle of 90 degrees where the two pieces come together,
with the crack at the bottom portion of the " V." This should
NOT be ground down to a knife edge, for it will readily burn
up. It is preferable to leave about one-eighth inch along the
line in order that the pieces will fit together and the proper
FIG. 45. Starting a Cast-iron Weld.
alignment may be obtained. If two pieces of cast iron have
been prepared in this manner the neutral flame of the welding
torch is brought down in such a manner that the tip of the
cone just licks the metal. The heat is not applied directly to
the line of weld to start with, but rather to the surrounding
part. This is done in order to get the entire locality in a con-
dition which will not withdraw too much of the heat from the
line of the weld, once the fusing is begun. If it is found that
the tip will not produce enough heat to bring the metal to a
red heat in a fairly short time, a larger tip should be used.
(73) No set rule can be given as to the sized tip to be used
on various kinds of metal. It will largely depend upon the
welder's ability and judgment. When the metal is brought
64 OXY-ACETYLENE WELDING MANUAL
to red-heat, the neutral flame or cone is brought into contact
with the lowest portion of the "V" and held there until
it is seen that the metal is, melted on both sides. The filler-
rod, which has previously been heated at one end and dipped
into the flux so that an amount adheres to the end of the rod,
then carries this flux to that portion of the weld which is
under way. Enough flux is blown off the rod into the weld
to clean up the surface and permit the metal flowing together.
The crack should be melted together all along before any
additional metal is added, for the elimination of the crack is
extremely important. It might be noted that as soon as the
metal begins to flow freely the neutral flame should be raised
a short distance from the work in order to better control the
FIG. 46. Reinforcing a Cast-iron Weld.
molten metal. In order to build up the metal to the original
state along the line of weld or perhaps 'reinforce it, the sides
and bottom of this " V-ed " out part are then brought to a
molten state arid held there while the filler-rod which brings
up more flux is stirred into this metal and the end melted off.
In this way the flame does not come in direct contact with
the filler-rod and is used only to keep the metal in a molten
condition. As much of the filler-rod can be melted off as is
thought necessary to bring the weld to the normal condition
of the metal or an additional reinforcement can be built up,
if it is thought advisable. If care is taken in the above pro-
cedure, many of the blow holes and hard spots in the weld will
be eliminated, for any impurities that might gather will be
WELDING OF CAST IRON 65
displaced by the melted metal and will float to the top.
In cooling a weld of this kind, care should be taken not to
permit any sudden chilling for this will tend to harden the
weld. It is best to cool it slowly by burying it in slack lime,
ashes, or wrap it with asbestos paper to keep the air from it
as much as possible.
(74) There may be a great many causes for blow holes and
hard spots in the weld, but probably they can all be traced
directly to the lack of heat. It must be remembered that
welding is a fusing process and heat is absolutely essential.
Therefore it should not be used sparingly. The application
of heat always causes expansion. There are no exceptions
FIG. 47. This Problem does not Require Preheating to Care for Contraction,
as the Ends of A and B. are not Confined.
to this rule, likewise upon cooling the metal there will be a
contraction. Outside of the actual welding, that is, the
fusing of the metal into a homogeneous mass, perhaps the
greatest problem that the welder has to confront is the expan-
sion and contraction of his metals. Whenever the ends of
two pieces of metal which are to be welded are free to move,
or even one end, there will be no difficulty encountered with
contraction and expansion, but if these ends are confined, it
is an entirely different problem.
(75) To illustrate this point more clearly, the following
very simple example will be given. In Fig. 47 we have two
bars of metal A and B which have been beveled off or " V-ed "
OXY-ACETYLENE WELDING MANUAL
out as shown at the point C. Now as soon as the heat is
introduced at C there is bound to be an expansion of the metal
at that point. Naturally if the pieces were heated slowly
and for a considerable distance, the cool ends of these bars
would be forced outward. We will assume that the heat is
introduced very rapidly and the metal is brought to a molten
state; that instead of the contraction forcing the cool ends
outward, whatever expansion there is, is taken care of,
at the weld, for the metal when melted will readily push to-
FIG. 48. Preheating Problem. Ends ofvBars A' and B' are Confined.
gether. It is also assumed that the bars are heavy enough to
overcome what slight force might be in evidence from the
expansion. A weld is then made and allowed to cool. As
it cools, there is bound to be a contraction along the line of
the weld and the welded piece will be slightly shorter than the
work before the weld, for it will draw in the pieces A and B.
As can be seen, there is no particular force preventing the
contraction of such a weld for the ends are free to move.
However, let us turn to Fig. 48, which constitutes an entirely
different problem. It might seem that the ends A' and B r
WELDING OF CAST IRON 67
appear the same as A and B in Fig. 47, but such is not the
case. The ends farthest from the weld are confined, held in
place by a heavy frame which does not permit their free
movement. When heat is introduced at the point of welding
C", about the same action takes place as in the previous
problem, but as soon as the weld commences to cool let us
see what happens. The bar A'B' must be shortened so there
is an inward pull on the bars D' and E' '. If this work were
cast iron or aluminum it would certainly be broken by the
strains set to working and would naturally break at C', where
the metal is still hot. If it were steel or one of the ductile
metals, it might twist and warp in its endeavor to overcome
these internal strains. This illustrates in a very simple
manner the difference between what is known as a " cold "
and a " preheating " job. In the first no provision is made
for expansion and contraction. In the second means are taken
to overcome these important factors. In order to provide
for the successful welding of the second problem, it is only
necessary to heat up the bars X and Y about the same distance
as the center will be heated, and keep them in that condition
while executing the weld atC', then allowing the whole to cool
PART Two. WELDING OF CAST IRON
(76) BEFORE commencing to weld, or even turning on the
gas, it is well to see that all preparations have been made and
all materials on hand to bring the weld or whatever job it
may be, to a finished state.
(77) As a specific example of a simple welding operation
let us consider that two cast-iron bars, measuring one by six
inches and twenty-four inches long are to be welded end
to end. To start with it would be necessary to " V " off the
?nds that were to be joined at an angle of about 45 degrees,
68 OXY-ACETYLENE WELDING MANUAL
leaving about one-eighth inch along the bottom edge to line
the metals up with and to see whether they are in proper
position. If the bar were to measure exactly forty-eight
inches when finished it would be necessary to move these
(Courtesy of Ben K. Smith, U. S. Welding Co.)
FIG. 49. This Locomotive Cylinder was Welded at the Saddle, near the
bars apart about one-sixteenth of an inch in order to provide
for their contraction. It is assumed that the weight of
the bars would be sufficient to prevent their pushing apart
when the line of the weld is brought to a molten state and that
WELDING OF CAST IRON 69
the expansion will be taken care of within the weld. The
bars after being lined up are ready for welding, but there
are such things as filler-rods, flux and goggles that are neces-
sary to have on hand before starting to work. It is well
to have a few fire bricks, a little asbestos paper and a bucket
of water convenient, in case these things are needed. The
acetylene gas should then be turned on and ignited. A suf-
ficient pressure should be passing through the regulator, when
using a medium, or high-pressure apparatus, to cause the
flame to leave the torch tip about twice the distance of the
diameter of the orifice of that particular tip. Then turn on
the oxygen until a neutral flame is obtained. On some
torches it is necessary to make a second adjustment by
turning on a little more acetylene gas and still more oxygen,
until a goodly sized neutral flame results. Apply the flame
to the pieces, so that the neutral flame will just lick the sur-
face of the metal. Move the torch slowly forward and back-
ward on each side of the " V " until the two edges are a dull
red color, or better still a bright cherry red, then hold the torch
stationary until the metal in the " V " nearest to the operator
commences to melt. Then bring the filler-rod end in contact
with the flame to get it heated and plunge it into the flux
which should be near at hand. Enough flux will adhere
to break up the oxides and by placing the rod between the
flame and the metal, enough flux will be introduced to allow
fusing of the metal. Proceed in this manner until the metal
in the bottom of the " V " is properly fused throughout
its length. Do not add the filler-rod, up to this point unless
necessary. In holding the flame, see that the preheating
flame will heat the parts yet to be welded. The weld should
be made away from the operator. After the metals along
the bottom have united and a good foundation has been
obtained, then start the weld at the beginning once more,
working the flame across the piece, in the same manner as
70 OXY-ACETYLENE WELDING MANUAL
before; bringing the metal to the molten state and stirring
the filler-rod in it. As the filler-rod melts, the amount of
molten metal naturally increases and the flame is moved
along the weld as fast as the metal is added. It is important
that the metal is in a molten condition. It is almost im-
possible to get too much heat on this type of work. Build
up the weld slightly higher than the original piece. It may be
found in finishing up the corners that the velocity of the gases
or the force of the flame will be sufficient to blow the melted
metal away. This may be overcome by directing the flame
at a different angle, and will cause no difficulty after a little
practice. Trouble, too, may be experienced on thin cast-
iron sections by having the metal collapse through the force
of the flame, but this can be remedied in the same manner.
While the weld is still in a heated condition, it is possible to
finish it by scraping the surplus metal off with the side of the
filler-rod, the chill of which has been taken off before it is
allowed to come in contact with the molten metal. Another
popular method that will produce even better results is to
use a very heavy rasp file to bring the weld down to the meas-
urements desired. During all of the previous operations the
flame never leaves the line of weld. When the weld is com-
pleted, the torch is shut down by turning off the oxygen
first, and then the acetylene, and the welded bar is covered
up to prevent its cooling too rapidly.
PART THREE. WELDING OF CAST IRON
(78) PROBLEMS in expansion and contraction should not
be difficult, if it is remembered that heat causes expansion
and the withdrawal of heat, or cooling causes contraction.
As previously stated, when the ends of the pieces which are
being welded are free to move, there is not much danger of
having contraction strains set up. Where the ends are con-
WELDING OF CAST IRON 71
fined, measures must be taken to overcome this. In welding
large pulley wheels, for example, it may be advisable to do
the job without taking time to preheat. Breaks may be
in evidence at any part of the wheel and generally the ends
are confined, such as in the case of a spoke. If it is borne in
mind that the expansion will take care of itself, the contrac-
tion is the only consideration, in a case of this kind. The
welder will see that if he can spring the edges apart a sufficient
amount to provide for the spoke coming back to normal when
welded, he will have no difficulty. The way to proceed in a
case, of this kind would be to open the rim by sawing it and
then introduce a jack or some sort of a wedge between the
hub and the rim. This will open the crack in the spoke the
amount desired. As soon as the weld is executed and while
still hot, the jack is removed to permit the rim being drawn
in. Later the rim can be welded, by introducing jacks be-
tween the spokes and the same procedure followed. It
always must be remembered that provision must be made
for the contraction, even though it be only one thirty-second
or one-sixteenth of an inch. The distance will depend en-
tirely upon the welder, as some operators use small tips and
cover a small area, while others employ larger tips and cover
twice the area. It is therefore impossible to set any specific
distance and each welder should try to figure this out for
(79) There are many jobs not of a preheating nature
that at times cause perplexity on the part of the welder. A
good example of this is a cast-iron gear wheel. A number of
its teeth have been broken out. Now there are three very
common ways of building up or repairing such castings.
First by aid of carbon blocks, cut to form and the teeth cast
in by the use of the torch; second, by blanking in the space
between the teeth and then sawing out the individual tooth
or cutting it out with a milling machine or shaper; third, by
OXY-ACETYLENE WELDING MANUAL
building up each tooth with the welding rod and torch,
and later dressing it down with a file. One very important
point must be uppermost, when dental work on gears is being
done, a good foundation is necessary, for regardless of how
well the tooth may be shaped, if it is not firmly secured to the
wheel itself, it will be of very little value. Another very
eld Eqttipment Co.)
FIG. 50. Large Cast-iron Gear Wheels. Although the Face on These Gears
Measured 10 Inches, New Teeth were Added by Blanking In, as Shown
in the Right-hand View, and Later Machined.
important point is in the finishing of such gears, to see that
the teeth which have been added correspond in the pitch
and mesh exactly as the others do. The importance of seeing
that things of this nature are machined correctly should not
require mention, but it has often been found that machinists
are very careless about finishing this kind of work and if
WELDING OF CAST IRON 73
anything goes wrong, the welder is naturally at fault. There-
fore it is always well to put the gears which have been welded
back into place and turn them over slowly by hand to see that
they are in good condition before the power is turned on.
In allowing this kind of work to cool after it has been welded,
(Courtesy of the Oxweld Acetylene Co.)
FIG. 51. This View Shows new Teeth being Welded in an 8^-ft. Cast-iron
Gear, Weighing over 5 Tons. Note the Improvised Preheating Oven.
some operators permit it to be hurried, with the result that
there may be hard spots to confront the machinist when
finishing. If he ruins one or two of his cutters he will naturally
frown upon all welding work. It is therefore desirable for
this and many other reasons to have the weld come out as
74 OXY-ACETYLENE WELDING MANUAL
soft as possible, and great care should be exercised in cooling.
Any weld that is subjected to machining, allow it to cool
slowly in slack lime, in ashes, or cover it securely with asbestos
paper. Occasionally it may be found difficult to find sections
of carbon blocks which will take care of a job of this kind.
Many welders who have had to run around the country,
and do jobs in isolated places, have found that the carbon
centers, from the ordinary dry cell batteries, which may be
found practically everywhere in a discarded condition, can
be shaped on an emery wheel and patched together in a manner
that will permit their use. However, when such are used,
it is quite necessary that they be heated a little with a torch
beforehand, in order to drive out any chemicals or acids
that may be contained in them. Unless these chemicals are
removed, the molten metal coming in direct contact with
them might be injured to a considerable extent.
(80) Ofttimes there are castings upon which parts wear
off in a very short time. There may be very little strain
upon these parts, yet the constant wear will weaken them in
time. It is well to remember the action of a carbonizing
flame when executing work of this kind. Introduce an
excess of acetylene when finishing up the work. It will be
found that with a strongly carbonizing flame, carbon will
be taken up by the molten metal and the finished weld will
be considerably harder and will wear longer than if it were
executed by a neutral flame. An abrupt cooling will chill
the metal on the surface and make it wear longer than it
WELDING OF CAST IRON
PART FOUR. WELDING OF CAST IRON
(81) THE true index as to the success of a weld will depend
entirely upon the finished job. If it is usable, i.e., if it can
be put back into service again and give satisfaction, it may be
considered a successful weld. If a piece were to be warped,
distorted, contain hard spots which could not be machined,
or have internal strains, which would not make it safe for
(Courtesy of Ben K. Smith, V. S. Welding Co.)
FIG. 52. View of Locomotive Cylinder with Three Jackets 3 Inches Thick.
This job weighed over 16 Tons and Required Fifty-six Hours of Welding.
use (such as fly- wheels), it could not then be considered
satisfactory and it would be only wasted energy. Perhaps
one of the most common jobs in the ordinary commercial
shop, and one which is the most abused, is the common cast-
iron cylinder block found on the gasoline engine. This is
so constructed that there are two walls of metal, very thinly
cast; the innermost being the cylinder wall, and the outer-
76 OXY-ACETYLENE WELDING MANUAL
most a water-jacket. The cylinder wall is machined very
accurately to accommodate pistons moving at a very rapid
rate, up and down and yet holding compression. The
upper part of the cylinder is called the head, and generally
has two or more valve seats which must be in alignment
with the valve guides to make an airtight seat for the valves.
Now this water-jacket is usually very thin, perhaps three-
sixteenths to one-quarter inch in thickness, and when there are
two, three, four, or more cylinders cast in one block, there are
bound to be internal strains set up in casting within the
piece itself. These strains are removed to a large extent
by baking the rough casting before machining. Generally
there are some strains left in every cylinder block of this
nature. If the water in the water-jacket freezes or some
other force comes in contact with the thin castings which con-
stitute a block, the metal will give way at its weakest point,
and the welder is usually called upon to repair it. At times
these cracks are exceedingly small and the temptation is to
braze or attempt to weld the small portions. However,
as soon as there is heat introduced into the water-jacket and
not into the cylinder wall, there are certain to be strains set
up which, if sufficient, will distort the cylinder and make it
useless unless it is rebored. The sooner welders realize that
work of this nature must be preheated throughout, to a
point as near melting as they can approach without causing
the metal to scale, before any welding is attempted, the
better success will be obtained in these lines. It is quite
necessary to line up the work well, so that it will not sag
when heated. It is best to heat very slowly and cool in the
same manner to insure the best results. There are many
preheating agencies, such as oil-ovens, preheating torches
and the like, but about the best and most reliable agent
known is charcoal, which heats up very gradually, makes
a good even fire and dies down slowly which is the manner
WELDING OF CAST IRON
8 OXY-ACETYLENE WELDING MANUAL
desired. Occasionally cracks will be found in the combus-
tion head of the cylinder. It is very difficult to get the
torch down inside the cylinder to execute this weld unless
the operator has a special torch for this purpose. Even then
it is difficult to keep the torch lighted when working over a
newly made charcoal fire. For this reason, other means
must be used when working on a job of this kind. First
the crack is accurately located, then a piece is cut out of the
water-jacket just over the crack by means of a chisel, hack-
saw or drill press. Never attempt to remove a piece of this
nature with the flame, for the introduction of heat may dis-
tort the piece at this time. " V " out the crack in the com-
bustion head and scrape off as much of the brown oxide and
dirt formation as possible. It is well to clean off more than
needed and to even " V " out the crack a greater distance than
is thought necessary. This will insure a good weld being
made in one operation. The cylinder is then preheated with
the crack uppermost so that welding can be executed with the
least possible difficulty. While preheating is taking place
it is well to tack the small section of the water-jacket which
has been removed, to the end of the filler-rod, and place it
too, in the preheating oven, with the end of the filler-rod
projecting so that it will be available whenever needed.
When the cylinder is red hot the weld should be executed;
particular attention being given to see that each part of the
metal is actually fused to prevent any leaks occurring later.
As a rule the welder can tell when he has made a successful
weld by observing the flow of his metal, and it will not be
necessary for him to test out this cylinder weld before adding
the water-jacket. The piece of the water-jacket is then
replaced; it can be very easily handled by means of the
filler-rod which has been tacked on. Weld this section securely
in place and cover the piece of work with asbestos paper and
permit it to cool with the dying fire. When cold, all port
WELDING OF CAST IRON
holes in the water-jacket should be closed and the cylinder
tested for leaks. This can be done by introducing water
into the water-jacket and applying
about fifteen pounds of air pressure.
Wet spots will appear if there are
any leaks. If the cylinder is found
tight it should be polished, then
oiled, and the outside given a coat
of filler or painted to make it pre-
sentable. Work is generally very
much discolored when coming out
of the fire. A simple device for
polishing the cylinder bore may be
made by turning out a hardwood
block about three inches long and FIG. ^.-Suggested Method of
a little less in diameter than the Polishing Cylinder Walls of
size of the piston. This should be Cast - iron Cylinder Block
,. . -r^. after it has been Preheated.
split as shown in Fig. 54, and
FIG. 55. Cast-iron Cylinder
Block with Part Broken
FIG. 56. Showing how Broken Part
on Cast-iron Block should be Lined
up before Welding. Position Great-
80 OXY-ACETYLENE WELDING MANUAL
wrapped with very fine emery cloth, then put into the cyl-
inder and a wedge placed between the two halves. Spread
them apart so they will come in contact with the cylinder
wall on all sides. A screwdriver may be used for this purpose
if necessary. By screwing this into the cylinder its full
depth, with the aid of a little oil, a very highly polished
surface may be obtained.
(82) Another cylinder block job that generally causes
more confusion than is necessary is brought about when
welding on small lugs, such as shown in Fig. 55. When
welding these lugs on from the outside only, they generally
warp upwards in cooling and it is either necessary to build
up the bottom side of this lug or to machine off the entire
face in order to have the end square. This can easily be
overcome by permitting the lug to sag before welding and
then dress off the small portion that continues to sag, after it
is welded, rather than face off the whole surface, See Fig. 56.
PART ONE. STEEL WELDING
(83) THE term " steel," as used in the following pages,
unless otherwise specified, will be the term applied to wrought-
iron and low-carbon steels. High-carbon and alloyed steels
are to be considered only in advanced work and will therefore
not be deemed a topic of interest to the beginner in laying
(84) The welding of steel is much more difficult than cast
iron on account of the many points which must be observed.
In cast iron the metal is brought to a molten state and may be
worked in that condition for some time without any apparent
change in the characteristics of the metal. A flux is used
to break up the oxide or scale and the metal will flow very
easily. The flux is necessary because the oxide has a higher
melting-point than the iron itself. When working on steel,
it will be observed that just the reverse is true, that its oxide
has a lower melting-point than the steel and consequently
no flux or cleaning powder is necessary when working upon it.
(85) A large quantity of steel kept in a molten condition
by the flame acting upon it is very easily influenced. The
same area is not kept in a molten condition as with cast iron.
The heat does not hold to the vicinity of the weld nearly
so much as in cast iron because of the greater conductivity
of the metal. If the flame is removed, the molten metal will
set almost immediately. This means that the flame must
be in contact with the metal at all times. It must be a
strictly neutral flame or else one of the two gases will be intro-
82 OXY-ACETYLENE^WELDING MANUAL
duced into the weld and its strength will be materially affected.
The size of this flame must be such that too great, an area
will not be covered, yet enough must be covered to keep the
metal along the line of the weld in a molten condition. If
a carbonizing flame is used, one which has an excess of acety-
lene, such as was shown in Fig. 23, much carbon will be taken
up by the metal, producing a brittle weld. If the flame is
oxidizing, that is, contains an excess of oxygen which is noticed
by the shortening of the flame and an accompanying hissing
sound, Fig. 25, the metal will burn and a white foam will
appear on the weld like a milky white glue. This tends to
weaken the weld. This same effect will be in evidence if
too large a tip is used. On the other hand if the tip is too
small not enough heat is obtained and the oxides and other
impurities which may be present will not be allowed to float
to the surface but will be trapped in the weld.
(86) The filler-rod used on steel should be as near the
same grade, if not better than the metal to be welded and
should be very low in its carbon content. A pure grade of
soft iron wire or mild steel will make a very good filler-rod
for ordinary purposes. The size of this filler-rod is very
important, for it should fuse at the same time as the metal
being worked upon, and unless it does this the weld will not
be satisfactory. If the filler T rod is too large it will not be
at the fusion point when the work is, and will not fuse with
it. If the rod is brought to a melting-point the work will
have too much heat and will burn. On the other hand,
if the filler-rod is too small, it will burn up before the work
is at the fusion point, or in other words, the work will still
be too cold when the rod is melted.
(87) There are many different methods of executing a
steel weld, and it has been noted that very few experienced
welders handle their steel in the same manner. Most of these
methods are very difficult to learn and can be perfected only
STEEL WELDING 83
after years of practice. However, a simple method which will
produce results is thought the most advisable for the beginner.
A careful examination and study of this point has brought
out the following method, which is very easily picked up and
which dispenses with most of the torch movements that are
generally advocated by the old time welders.
(88) When welding two pieces of steel bars, the cross-
section of which will measure one-half inch by three inches,
they are beveled off and prepared in the manner illustrated
in Fig. 57, either by means of a chisel, file, or by the use of a
grinding wheel. About an eighth of an inch of the original
FIG. 57. Preparing and Heating Steel before Welding.
stock is left on the bottom side and the angle formed from
these two places when brought together, should be 90 degrees.
When the pieces have been prepared and placed in the posi-
tion shown in the illustration,- the neutral flame is then
brought down at right angles to the plane of the metal, so that
the end of the cone will just lick the surface. It is moved
up and down upon each side of the part to be welded until
each piece is brought to a red heat, for a distance of at least
one inch back. The position of the torch during this opera-
tion can be seen in Fig. 57. From this time on, the operator
should work as rapidly as possible, for the quicker the fusion
84 OXY-ACETYLENE WELDING MANUAL
of the metal is brought about, the less oxide or scale will
appear and a better weld will result. The description of
this process may take some length but the actual fusion not
nearly so long.
(89) When the red-hot stage is reached, the neutral flame
is brought down to the very lowest part of the " V " at the
side nearest the operator and held there until the metal has
melted and is about to collapse. The flame is then quickly
twisted away for just a second to let the metal set. Perhaps
FIG. 58. In Welding Steel, the Beginner Should Fuse His Pieces together
aldng the Bottom with the Torch Flame, Adding no New Metal. The
Metal on Both Sides of the Torch Flame is Melted together until a Small
Pool of Molten Metal Appears, then the Torch is Twisted Smartly away,
as Shown by the Arrow, and the Metal Allowed to "Set" for an Instant
before Proceeding along the Line of Weld.
this operation will fuse about one-half inch or less along the
bottom of the " V." This same operation is repeated along
the line of weld until the whole piece is fused along the bot-
tom. It will be noted that no filler-rod has as yet been used.
After the last portion has been fused, the flame is brought
back to the starting-point and played not only on the bottom,
which has already been fused, but on the sides of the " V "
as well, bringing an area of about one inch in diameter to a
molten condition. The tip of the welding torch is held in a
vertical position all this time to Introduce as much heat into
STEEL WELDING 85
the weld as possible. During this operation the filler-rod,
which should measure three-sixteenths or one-quarter inch
in diameter, is picked up by the operator's free hand and its
end brought near the heat of the flame so that it may be
warmed and will not chill the metal when introduced into the
weld. When the melted metal is running freely, the tip of
the welding torch is slowly inclined in the direction of the part
to be welded and is advanced along the " V-ed " out portion
at this angle as rapidly as the metal can be made to melt.
This position is shown in Fig. 59. It will be noted that
FIG. 59. Method of Adding "Filler-rod" in Welding Steel. Note that the
Rod is Worked behind the Flame.
as the flame advances along the line of the weld the molten
metal will mount up behind it of its own accord, providing
the metal is in a molten condition, when the flame passes over
it. During this period the filler-rod is stirred into the molten
metal in a circular movement which should be in back of
the torch as much as possible. This means that the torch
comes in contact with the filler-rod but very little and the rod
is melted, not by the flame, but by the molten metal of the
piece being welded. It will be noticed at times, when too
much metal has been welded and the torch is not advancing
rapidly enough, that some of the molten metal will run ahead
86 OXY-ACETYLENE WELDING MANUAL
of the flame, into that part of the " V " yet to be fused, and
to the unwary student this will be looked upon as a safe place
to add his filler-rod. However, when the piece is broken
and the cross-section of the weld examined, it will be found
that in this part of the weld, the metal has only been laid on
and not fused. The beginner should watch this operation
and see to it that this molten metal is not permitted to run
ahead of his torch, an act which he can overcome by the proper
manipulation of his filler-rod, which really governs all the
melted metal behind the flame. If not enough metal has
been added to fill in the " V " to the proper thickness, this
FIG. 60. This Method of Adding the "Filler-rod" when Welding is not
Recommended for the Beginner.
operation can be repeated until enough metal has been added.
By practicing this method the student can be taught to
execute a very successful weld and reinforce it all in one
operation without any chance of burning his filler-rod or
lapping his metal. More practice is required to successfully
weld steel than most other metals and the beginner should
not be discouraged if it takes him some time to conquer this
metal. It should be forcibly impressed on the student
that the metal must be in a molten condition before the filler-
rod is added, or else it will stick and prevent his working
readily and in addition will produce a very faulty weld.
STEEL WELDING 87
Fusion is the thing to bear in mind for without it success can-
not be expected.
(90) While outside appearances should not be considered
as a prime requisite, when beginning it is always well to add
more metal than is really necessary in order to reinforce the
weld as much as possible. It cannot be expected, however,
that a steel with the same cross-section as the original will
possess the same properties and be as strong, for a weld is
only a casting unless treated otherwise and the steel or wrought
iron used in the specimens is of rolled stock. If too much
metal has been added and dressing down is necessary, the
student will find that by using a slightly oxidizing flame the
surplus metal can be burnt away very rapidly and a very
good-looking job can be executed much more rapidly than if
a neutral flame were used. It is well to remember, however,
that this is used only in dressing off pieces and in places
where the strength of the weld is not to be jeopardized.
(91) When advancing in steel work, it will be noticed that
the same provision for contraction and expansion is not con-
sidered in as great proportions as on cast iron, and the reason
is quite evident. In cast iron we find the metal is very
brittle and will not give without breaking, whereas on steel
it is more ductile and will twist and bend before breaking.
This does not mean, however, that the important points of
expansion and contraction are to be neglected in steel work,
for they are very important; as we shall see later on.
PART Two. STEEL WELDING
(92) IT is still supposed that the beginner knows very little
about the various kinds of metals, or methods of distinguish-
ing between them. This is of great importance and should
at once be overcome, as he will not at all times have someone
over him to diagnose his case and tell him the proper procedure.
88 OXY-ACETYLENE WELDING MANUAL
For instance, were he to be given a piece of cast steel to weld,
thinking that it was cast iron, he would use a cast-iron
filler-rod in executing his weld. The results of such a weld
would not be very favorable, and the same would hold true
if a steel filler-rod were used on cast ifon. An occasional
glance at the table in paragraph 67 will acquaint him with the
various tests to make when deciding upon the nature of
the piece to be worked upon. The tests should be applied
in every doubtful instance. When working on cast steel,
a student may think that he must have a cast-steel filler-rod,
but this is an exception to the general rule and he can use
the same style filler-rod as he would employ on ordinary
steel work. It might be mentioned here that when working
on alloyed and high-carbon steels, the filler-rod generally
contains some of the alloy or carbon which will tend to
replace that destroyed by the action of the flame in the origi-
(93) In welding cast steel the same procedure takes place
as -previously described for steel, and it should present no
real difficulties after that process is understood. There may
be more sand, oxide and other impurities present on account
of the nature of the metal, but these can all be worked out
if plenty of heat is applied. At times, when working in steel,
it will be found that there may be a small hole develop in
the center of the weld and as the torch is worked into this
hole it is found that it goes down a short distance and seem-
ingly refuses to be worked out. This is what most welders
call a " crater," and is caused by the metal at the bottom
not being hot enough for the surrounding melted metal to
fuse it. When found they should be removed before adding
any more metal. By playing the torch flame around and
around it, so that the heat may be transmitted to the bottom
of the " crater " and it brought to the melting-point like
the surrounding metal and suddenly jerking the torch away,
STEEL WELDING 89
it will disappear. " Craters " are generally formed during
the first part of the weld, especially if the " V " is narrow,
and they are hard to handle when deep. Under no circum-
stances should the filler-rod be melted into them in trying to
make them disappear, as this will only mean covering them
(94) Some welders find that hard spots develop in their
welds which they have difficulty in overcoming, and it is a
very serious handicap when the weld is to be machined, for
ofttimes it will break very expensive tools and leave a
portion of a drill or die broken off in the metal. It is prob-
ably safe to say that the principal cause of hard spots in steel
welds is due to lack of heat. This, if given careful thought
and consideration, will be brought home forcibly to the welder
as he proceeds in his work, for the lapping of metals, trapping
of oxides, " craters," too rapid cooling, etc., may all be
directly attributed to a lack of sufficient heat. If the metal is
in a molten state, all impurities will be brought to the sur-
face, for they are bound to be displaced by the weight of the
metal, the same as corks in a barrel will float to the top if
water is introduced. The water in this case has a greater
specific gravity than the corks.
(95) In welding on sheet iron and steel, many operators
will find that they have more difficulty in executing a suc-
cessful weld than on slightly heavier work. This is no
doubt due to the thin nature of the work and the ease with
which it may be burned or carbonized if the operator is not
alert. When working on such material a very small filler-
rod is used if thought necessary but this rod must be as
free from impurities as possible. When working on a long
seam such as may be encountered on a steel tank, it will be
noticed that in welding from one end along the seam that the
metal ahead of the flame will tend to overlap as shown in
Fig. 61. This may be overcome by tacking (that is, fusing
90 OXY-ACETYLENE WELDING MANUAL
the metals together), at various points before starting the
weld, or the parts ahead of the torch can be separated as is
shown in Fig. 62 and held this way by using a wedge. This
is moved along as the weld advances and permits the edges
to close together. Another method used by manufacturers
who make a specialty of this work is to construct a jig which
FIG. 6 1. The Open Ends on long Steel Welds will Overlap as the Welding
Progresses if Improperly Started.
FIG. 62. Showing how Open Ends of Steel pieces are Spread Slightly to Over-
come Lapping of Ends in Making Weld.
clamps the ends rigidly and they are welded while in this
position. This phenomenon in steel welding will appear
rather strange to the welder who has had some experience on
thin cast-iron work, such as oven doors and the like. In
these he found that as his weld advanced, the welded portion
before him would separate, and when he had welded about
four inches or so it would be necessary for him to jump his
flame back to the beginning of his weld and heat up that
portion, in order to close up the cracks before him previous
to his continuing the work. This is illustrated in Fig. 63.
This may be explained by the fact that steel is a very
ductile metal and when it is fused, the expansion is taken
care of internally by the two edges combining. Then, in
cooling, the metal contracts, an action much more rapid in
steel than in cast iron, and draws the edges of the steel plates
past each other so that they overlap. In cast iron, which is
FIG. 63. This Illustration Shows how the Open Ends of Thin Cast-iron
Pieces Spread apart as the Weld Progresses. To Close the Edges to-
gether, Jump the Torch Flame from B to A; as A heats up, B Cools
and the Lever-like Action Closes the Opening.
rigid, the edges are expanded by the fusion of the metal and
this space is then filled up with new metal, holding the edges
apart. As the weld progresses the metal ahead of the torch
is pushing out, and that behind is cooling off, which acts as
a lever on each side to open up the unwelded ends.
(96) To weld a broken automobile frame successfully
the body of the car should be raised if necessary, to keep it
from burning and all pipes, wires and gasoline leads pro-
tected with a covering of asbestos paper. Plenty of room
should be allowed, so that the welder may have easy access
to the break, and the frame should be jacked up on both sides
92 OXY-ACETYLENE WELDING MANUAL
of the break until the frame is in proper alignment. Then
weld the crack from the outside, working across the top,
then down the side and across the bottom, reinforcing a
little if necessary on all sides but the bottom. Then repeat
this operation on the inside, reinforcing at all points. Then
take a strip of steel about one-eighth or one-quarter inch
thick and six or eight inches long and as wide as the bottom
FIG. 64. A Good Method of Reinforcing a Weld on an Automobile Frame
is Here Shown. The Patch as Pictured Here is only " Tacked On." It
Should be Welded Securely to the Bottom of the Frame on all Four of
of the frame. This piece should be welded securely to the
bottom of the frame with the former break in the middle of
the strip. A cut representing this job is shown in Fig. 64.
By this method the frame can be made stronger than origi-
PART THREE. STEEL WELDING
(97) ASIDE from the difficulties already mentioned in steel
welding, there are many others. A few of these will be taken
up in order to let the beginner know how to approach the
various problems which may confront him. But in no wise
is this to be considered to be a treatise on advanced work. Oft-
STEEL WELDING 93
times the question arises, Can springs be successfully welded?
Now, while springs have been welded, and they have been
tested out thoroughly, yet the practice of spring welding
with the oxy-acetylene flame is not to be recommended.
There are those who will weld leaf springs, such as are found
on automobiles, and will apply rapid blows with the hammer,
while their weld is still in a heated condition and then plunge
the spring in water or oil to harden it and the weld. A
close observer will readily see why this procedure is not
correct. Springs of this nature are made up of metal which
takes a uniform hardening, and were it not so they could not
be considered springs. Now, if there is a fracture and a
foreign metal, which under no circumstances can be expected
to take the same hardening as the rest of the spring, is intro-
duced into the weld, it can easily be seen why a fusion of this
kind is not to be relied upon. If it were possible to diagnose
or take an analysis of the metal in the spring and use a filler-
rod which, after being acted upon by the flame, would come
out the same as the metal in the spring, then some success
might be expected, but until that time, welding of springs
will not be encouraged. Unless perchance the break is of
such a nature that it can be reinforced readily and is in
such a position that a resilient quality is not necessary.
(98) Work on crank-shafts often causes perplexity on the
part of the beginner, for he usually hears this matter discussed
pro and con. Crank-shafts of four inches in diameter can be
successfully welded with the oxy-acetylene flame, and even
larger, if correct methods are employed. There are many
points which the welder considers before deciding whether a
weld of this nature is advisable. Of course the usability of
the piece after it has been welded is the main issue when
executing any kind of a repair job. Now, a crank-shaft
will generally break in either of two ways; by some external
force, such as a connecting rod breaking loose, or by crystalli-
zation, which is usually due to fatigue. Now, in the latter
94 OXY-ACETYLENE WELDING MANUAL
case, ofttimes the shaft will break in the cheek of the ''off-
set," and possibly no part of the shaft is thrown out of align-
ment. When such is the case, welding is usually recommended
and the shaft may be brought back to a useful state in very
quick order. However, in the former case, the shaft is apt
to be sprung, and while it could be welded, the machine
work necessary to restore it to normal requires much time,
and it has been known, where after spending a matter of
days in trying to get proper alignments, work was scrapped as
useless. So it is entirely up to the welder in work of this
FIG. 65. Building Up Worn Shafts.
kind to determine whether the job is worth while or not.
There are certain parts of a crank-shaft upon which welding
work can be done with a marked degree of success, such
as building up worn bearings and the like. In doing work
of this kind it is recommended that the welder fuse his metal
in a line parallel to the center line of the bearing, seeing to
it that he has a perfect fusion between the surface of the bear-
ing and the metal he is fusing and adding plenty of metal,
to insure enough being used, so that no low spots will show
up when it is machined. It is considered that by adding the
metal as suggested the welder will hold his heat much better
than if he attempted revolving the shaft continually. Fig.
65 will show the method here outlined in a very clear way.
(99) When working on shafts the welder will encounter
such articles as automobile propeller shafts and rear axles,
which generally break adjoining the square ends. He will
no doubt wonder whether it is advisable to weld this square
end back on, or whether to try and build up the shaft the
desired length. Undoubtedly the point of fracture is the
FIG. 66. Shaft Broken at End of Square Shank, its Weakest Point.
FIG. 67. Broken Part of Shaft Removed and New Piece Added, thereby
Moving the Weld away from the Weak Part.
weakest portion of the entire shaft, else it would not break
there. The execution of a weld at this point where no
additional metal can be added or any means of reinforcing
used is not to be recommended. Fig. 66 will show the problem
which confronts the welder, and Fig. 67 the suggested means
of overcoming the difficulty. By removing about four inches
from the broken end of the shaft and adding a new piece,
about ten inches long, of the same diameter, the weld will
be removed from the weak point; a heavier weld can be
made, and the end can be machined off to the desired size.
This procedure is recommended on all jobs of like nature.
96 OXY-ACETYLENE WELDING MANUAL
(100) Occasionally case-hardened ring gears are brought
to the welder to have teeth built up or new ones added, and
although the welder must realize that the hardening is de-
stroyed by the action of the flame, yet he does not under-
stand why it is necessary to reharden the gear. A little
thought on this subject will make him appreciate the fact that
if he destroys certain properties in metal which have been
introduced for a reason, these must be replaced if he would
bring the job back to normal. It would be like heating up a
tempered lathe tool, or cold chisel for that matter, and try-
ing to use it before it had been retempered. Therefore if
FIG. 68. When Welding a Small Section to a Larger One, the Flame of the
Torch is Directed toward the Heavier of the Two.
hardening or temper is destroyed by the flame it must be
(101) If a weld were to break, it would be necessary for
the welder to remove all metal added in the first weld before
attempting to reweld. This is true of his own work as well
as that of others which he may be called upon to do. For
no matter how good the surface may appear, without a solid
foundation no weld is of any value, and unless he clears out
all of the old metal he cannot be sure of the work. This will
apply not only to steel work, but to all metals, and it is a point
which should be borne in mind.
(102) At times there are jobs come up in which one piece
STEEL WELDING 97
of work is to be fused to another which is much larger, and
will absorb much more heat during the weld. When hand-
ling such work, it will be necessary to play the torch upon the
larger piece most of the time, as shown in Fig. 68, in order
to bring both pieces to a fusion point at the same time and
keep them in that condition.
(103) Once in a while it will be necessary for a welder to
fuse cast iron to steel or vice versa, and the question will arise
as to which filler-rod he will use. It has been found that
a cast-iron filler-rod can be used with success and of course
when using a cast-iron filler-rod, a cast-iron flux will be neces-
sary. Work of this nature is not very frequent.
PART FOUR. STEEL WELDING
(104) WHEN steel is in a melted condition, it seems to
be in a very susceptible state. It appears to absorb gases,
and with constant working an oxidation is in evidence which
materially effects the strength of the metal.) When working
o vanadium and other alloyed steels, if kept in a molten
condition too long, many of their principal characteristics are
destroyed.! For this reason it is advisable to execute steel
welds just as rapidly as possible. While this is true of most
work, it is especially to be emphasized on steel. To assist
the welder in executing welds on large steel castings, the pieces
are generally preheated, so that the work will take less time,
be more successful, and save both oxygen and acetylene.
When working on preheated jobs, in order to get the desired
angle on the filler-rod so the welder may use it without dis-
comfort, a light heat is played on the filler-rod, a matter of
six or eight inches from the end being fused and then bent
to an angle of 90 degrees, so that . the operator may hold
the rod at some distance from his work and still introduce
it in the manner he desires. Some operators weld their cast-
98 OXY-ACETYLENE WELDING MANUAL
iron filler-rods together, to get the desired angle as shown in
Fig. 69, but this is not as common as the steel method,
probably because cast iron will not bend and it requires some
time to weld the rods together in this manner.
(105) In some parts of the country boiler flues are
acted upon and eaten away by the impure water used, and
when high prices prevail, re tipping is generally resorted to. A
simple method in which they can be satisfactorily and cheaply
FIG. 69. Kinks for Handling "Filler-rod" on Large Work to Remove Welder's
Hand away from Heat of Flame.
(a) shows how the steel "Filler-rod" is heated by the torch flame about 6 inches from the
end and bent to the angle desired.
(b) illustrates how cast "Filler-rods" are handled. Since they will not bend, they are welded
in the T shape shown. First one side is used in fusing, and then the other.
done is as follows: Cut off the poor end until solid metal
is reached, with a pipe cutter, which will tend to " V " the
work as it cuts and at the same time will squeeze the edge of
the pipe in. After cutting, this end of the flue is placed on
the horn of an anvil and the burr on the inside, which has been
made by the cutter, is flattened out. It is very important that
the flue be of the same size throughout in order to permit
its being cleaned. It is then placed in " V " blocks or a
STEEL WELDING 99
trough, made of angle iron, such as shown in Fig. 70, and the
new end which has been prepared in much the same way
is placed in the position shown in A in the same figure.
The piece is tacked on at two or more spots and then laid
aside until the whole set of flues has been prepared in this
manner. Then they are replaced in the trough and welded,
one after another, being turned at one end by a helper, thus
allowing the welder to do continuous work. Care must
be taken at all times that perfect fusion takes place between
the flue proper and the piece being added, yet at no time
should the metal be allowed to run on the inside of the pipe.
More metal can be added than is really necessary and can
FIG. 70. Showing a Simple Way to "Line-up" Flues when Retipping.
B Represents the old Flue, and A the New Piece to be Added.
later be dressed down on a grinding wheel to the desired size,
which must be such that replacement of the flue can be made.
Various-sized pipes can be welded in much the same way
where no reducers are obtainable, the only change being
that there must be a step made in the trough which will
permit the various-sized pipes being lined up correctly.
Jigs for the speeding up of manufactured articles which are
to be welded are always being brought out by the ingenious
workman and are to be encouraged whenever possible.
(106) In the repair of boilers many a feasible job has
OXY-ACETYLENE WELDING MANUAL
been given up as impossible by the unthinking welder.
Cracks have been found in fire-box sheets around the stay-
bolts which, as soon as they are touched with the flame,
seem to run and keep running. They really discourage those
who are not familiar with this class of work. Many such
welds have been executed and are apparently all right until
tested, when they give way and make the job worse than it
(Courtesy of the Oxweld Acetylene Co.)
FIG. 71. Welded Cracks between Staybolts.
was previously. The trouble is in these instances that the
welder has made no provision for contraction and while
the job might appear to be successful, yet the internal strains
exerted will not show themselves at the test. Many boiler
shops have found that the flat patch is not to be relied upon
and when a crack is found between two stay-bolt holes,
such as shown in Fig. 72, a round hole is cut as shown by the
dotted line. A circular plate is then cut slightly larger than
this hole and after being brought to a red heat, it is bellied
by the use of a hammer or a set of dies, so that it assumes
FIG. 72. A Crack between the Staybolts in a Boiler should be Cut Out as
Shown by the Dotted Line, to Prepare it for a "Dished" Patch.
FIG. 73. A "Dished" Patch.
the shape of a saucer and is called by many a " dished "
patch. Some idea may be had of such a patch from Fig. 73.
(107) The patch is placed in the sheet with the concave
side toward the operator and should be securely welded in
place, adding as little metal for reinforcement as possible,
p K)2 OXY-ACETVLENE WELDING MANUAL
but seeing to it that a perfect fusion is made between the
patch and the sheet all the way through. As soon as the
weld is complete the torch is played upon the high part of the
patch, which is protruding, and as the weld cools off, sharp
quick blows can be applied to the center of the patch, which
should be kept in a heated condition until it is nearly flat.
This will take care of any contraction that might set up and
is a very good way of handling patches which do not exceed
six or eight inches in diameter.
(108) A " corrugated " patch has been brought out more
recently than the " dished " patch, and as its name would
FIG. 74. A "Corrugated" Patch.
indicate, it has corrugations around at least three of its sides.
While a " dished " patch is limited in its scope and cannot
be applied to square holes unless the square holes be cut
round, the " corrugated " patch knows absolutely no limits
as to size or shape. While its preparation is probably more
difficult, yet its purpose is the same, that is, to take care of
the contraction which takes place in sheets of metal where
heat has been introduced. To prepare a "corrugated"
patch, a piece of metal which is somewhat larger than the
hole is taken and the corrugation is made by placing two rods
on one side and somewhat separated and between them on the
other side another rod. With this section of the patch
heated to a red heat, a drop hammer is played upon it and
STEEL WELDING 103
a corrugation effected. Or an easier method is by the use of
specially prepared dies, which will turn out a patch in quick
order. It must be remembered that while the patch shown in
Fig. 74 is only for a very simple job, which is rectangular
in shape, yet " L " shaped patches can be prepared and
handled in the same manner. When the corrugation has been
introduced into the patch, the latter is cut so that it will
fit the hole, and it is tacked in position with the bellied
sides out. The method used in applying a patch of this kind
is to weld the uncorrugated side, then start up the corrugated
side and weld for two or three inches, then play the torch
upon the corrugation, adjoining the part welded, and slightly
hammer to assist in the expansion of the same; then return
to the weld, continuing it until the corrugation can again be
played upon. By doing this, when finished the patch will
be flat and no signs of the corrugations will be shown. While
many patches of this nature are in use giving the very best
service, the welder who looks upon the finished job cannot
tell how it has been accomplished.
(109) While the methods here given seem only to apply
to boiler work, they are not so restricted and can be applied
to tanks and various vessels with success. However, when
welding on tanks which have contained inflammable gases or
gasoline the welder is cautioned to take every measure to
safeguard himself, and while it is known that much work is
being done on such jobs, it is not recommended and in fact
quite the contrary. It is true that there are such methods as
filling the containers with water; cleansing with live steam,
and so forth, but the cautious man will refrain from working
on these vessels even though such measures have been
taken. Gasoline has a faculty of penetrating the pores
of metallic surfaces, and although these vessels have been
emptied and have remained so a matter of a year, the gaso-
line is still present to some extent, as is evidenced by the
104 OXY-ACETYLENE WELDING MANUAL
fact that as soon as heat is applied and the molecules of the
metal are expanded, the gas is released in sufficient quantities
to cause an explosion. This is not in one instance only,
but in many, so it has been thought best to discourage any
welding work on vessels which have contained gasoline at
(no) While it is possible to weld cast iron on the vertical,
by the use of carbon blocks and so forth, the same kind of
work can be accomplished on steel with much ease, without
the use of any blocks, or materials other than the filler-rod
FIG. 75. Working a Vertical Weld on Steel, from the Top Down.
and the welding torch. There are two methods of handling
vertical welds; welding from the top down, or starting from
the bottom and working up. The former seems to be con-
demned by those who have never tried it, on account of the
carelessness which is apt to be used on work of this kind. How-
ever, for the beginner, it is thought advisable to teach this
method, as there are many places where it can be used ad-
vantageously. The metal at the top of the seam, such as a
broken automobile frame, or the like, is brought to a molten
state and held there, not only by the velocity of the flame,
but also by the filler-rod, as is shown in Fig. 75. With the
STEEL WELDING 105
choosing of a tip of the correct size, the melted metal can
be held under control with much ease, after a little practice,
and it is allowed to descend as soon as the metal below it
is in the proper shape for fusion. The filler-rod is added
continually, for it is never lifted out of the molten metal,
merely stirred a little from side to side as it descends. None
of the melted metal is allowed to precede the flame, and at all
times the operator can see whether the edges to be fused are
at the right heat. As soon as the bottom is reached, the weld
can again be gone over if it is not thought strong enough,
and reiniorced as much as desired. As soon as the operator
is familiar with this method, he will find that much more
speed can be developed, less filler-rod lost and less lapping
done than by building up from the bottom.
(in) In welding over head there is a tendency on the
part of most welders to avoid the use of enough heat to bring
their metal to a molten state, for fear that it will drop upon
them. It must be remembered thai lack of heat means poor
welds and that the metal must be in a molten condition when-
ever the weld is to be made. As soon as a little practice is
given to this kind of work, the welder will see that the melted
metal can assume some proportions without dropping off,
despite its weight. It has probably been noticed that on
" sweating " water tanks drops of water accumulate on the
bottom of the tank and do not fall off. It is the same sort
of problem in the case of melted steel. The adhesion of the
molecules and the surface tension are the forces that keep the
metal from dropping.
(112) IT is difficult for the beginner to accustom him-
self to brass welding, especially on large work. While he
has been taught to believe that brass has a much lower
melting-point than iron or steel, yet when he comes face to
face with the actual problem of melting it, he will find that
it is necessary to hold his flame in contact with his piece much
longer, on brass work than on either of the other two, before
the melting point is reached. This can be accounted for by
the great conductivity of brass. On cast iron and steel
the heat was rather local, but on brass work it is transmitted
to all parts of the piece as rapidly as it is introduced, and this
absorbing process continues until practically the entire piece
is near the melting point.
(113) Brass has for its base, copper to which an alloy
of zinc has been added. Now the most difficult part of fusing
brass work, is to add more metal from the filler-rod to the
parts which are to be fused, without burning up any more
of the alloy, than is absolutely necessary. Seeing that the
copper and zinc have different melting points, it is a very
difficult feat and requires considerable practice. Much of
this trouble can be eliminated by the use of a filler-rod which
has the correct proportion of alloy added, so that it may take
care of and replace any that has been destroyed by the flame.
(114) Brass work is " V-ed " out when welding is to be
done, in practically the same way as cast iron. Only under
no circumstances should the ends of the parts be burned
BRASS WELDING 107
off, when " V-ing," as the heavy oxide which is deposited
on the remaining metal is very hard to combat with the weld-
ing flame. The ends of the work are brought to a red heat
with the flame that is slightly carbonizing. This is held
directly in contact with the work during the preheating
stages, in much the same manner as on cast iron, and a small
layer of carbon may be seen to accumulate around the weld.
Now, in theory, this would seem the worst thing possible to
have present, but in practice a small quantity of this soot
acts as an aid in making the weld, besides making the flame
less intense, which saves much of the alloy, from being
burned when the fusion occurs. When the ends have become
red hot, the same procedure is used as in working steel,
except that the torch is given a slightly greater angle and a
brass flux is used.
(115) Contrary to most authorities we find that an
abundance of good flux is desirable on brass work and that
it is almost impossible to use too much. It is desirable
to use only the best welding fluxes, for the best welds are
to be insured only under ideal conditions. If a welder were
to run short of flux, however, he might use powdered borax
of the 20 Mule Team variety, to tide him over until he could
get a new supply. The flux is added in the same way as the
cast-iron flux, that is, by dipping the heated end of the filler-
rod into the flux container. Enough will adhere, and when
added will clear up the metal in the vicinity of the weld. It
should be added as often as a welder notices his metal needs
cleaning and this will vary depending upon whether there is a
slow or rapid worker behind the torch. A man must use
his own judgment in cases of this kind. Remember that
the flux is a cleaning agent and if the surface is clean, no
additional flux is necessary, but if the contrary is true, that
is, if the surface is full of oxide and the filler refuses to flow
easily, flux is necessary and should be added.
108 OXY-ACETYLENE WELDING MANUAL
(116) During the welding, dense white fumes will come
from the fusing brass. This is the burning out of the alloy,
that is, the zinc. These fumes are injurious to the welder and
should be avoided, if possible, by proper ventilation. The
use of a proper filler-rod and rapid work will largely tend to
overcome the presence of these fumes, but if the operator
is very slow, they will appear, and are followed by a porous
and brittle weld, which if broken afterwards will show a
large number of blow holes. The most difficult part of brass
welding as a whole is to add the filler-rod, being certain of a
fusion, without burning out the zinc. When brass is in a
heated condition, it is very fragile and will crack readily
if disturbed. All precautions should be taken to see that no
sudden jarring is given the piece until the weld has completely
set. When this work is done many welders plunge their work
in water, in an effort to make it more ductile and easier to
machine. While this, of course, is condemned by theorists
and rightly so, in practice there seems to be no injury results.
PART ONE. ALUMINUM WELDING
(117) So far as the actual fusion of aluminum is con-
cerned, it is probably more easily learned than any other
metal, but on account of. the rapid conductivity of heat and
the loss of most of its strength when heated, aluminum has
caused much concern among oxy-acetylene welders.
(118) There are two methods used in welding aluminum,
the flux method and the puddle method. The puddle
system gets its name from the use of a puddle stick or spoon-
like rod which is used to stir the metal together, and is very
satisfactorily used on all cast aluminum. The flux method is
applied to both cast and sheet aluminum and it is so-called
because a flux is used to break up the oxide along the line
of weld. The discussion to follow applies only to cast
aluminum. It is in this metal that most interest is centered,
as the welding of sheet aluminum, such as is found in auto-
mobile bodies and some cooking utensils, is not encountered
in the ordinary run of work.
(119) When working with the flux method about the same
sized tip is used as when working on cast iron. This is applied
to the line of weld and held there until the oxide on the sur-
face commences to wrinkle and small globules of a mercury-
like appearance form on the surface. When heat is intro-
duced in aluminum it is transmitted throughout the piece
in the. same manner as occurs in copper and brass, therefore
it will require much more time to heat the work than the same
sized piece of cast iron or steel. As soon as the weld assumes
OXY-ACETYLENE WELDING MANUAL
ALUMINUM WELDING 111
the condition mentioned, fast work is necessary or the metal
will collapse, for it loses most of its strength when heated to
this condition. The end of the filler-rod bearing the flux
is brought down on the metal and immediately the surfaces
will clear up and run together, like so much mercury. The
torch is instantly jerked away and applied farther along the
weld. The theory of this reaction is that the heavy alumi-
num oxide is the only thing which prevents the metal flowing
together when heated, and as soon as the flux is introduced
this oxide will be destroyed along the line of weld and a fusion
of the metal effected. This actually takes place, providing
enough heat has been introduced to permit this reaction to
penetrate the depth of the weld. The flux contains the
chemicals necessary to cause this reaction if the metal is
in the right condition. There are many welders who do not
use sufficient heat and blame the faulty results upon the
flux. On the other hand, there are many fluxes which are
absolutely useless in performing a function of this kind.
The chemicals necessary in compounding a good flux for
this class of work are expensive and therefore this flux cannot
be procured at a low price. When the weld is finished and
cooled the surface should be scrubbed with soap and water
to remove all traces of the flux, otherwise a corrosion may
occur a month or so afterwards, and while it may not affect
the weld in any degree, the owner of the piece may not be
pleased at the sight. It is therefore advisable to remove all
traces of flux used on aluminum work.
(120) The puddle system differs from that of the flux,
insomuch that when the metal has been brought to the
same heat, where the flux has been applied it will be found
that the metal is really in a pasty condition. It can be
stirred together and the break entirely eliminated by the use
of a puddle stick, either of a pointed or a flat spoon-shape
design, as shown in Fig. 77. During this puddling stage,
112 OXY-ACETYLENE WELDING MANUAL
the torch is usually held in the left hand with the flame some
distance away from the work, only introducing enough heat
to keep the puddle pasty. The puddle stick is handled
by the right hand and when extra metal is needed the puddle
stick is laid aside and the aluminum filler-rod is picked up
and worked into the weld. When sufficient metal has been
added the puddle stick again comes into play and can be
used in stirring the metal together and finishing it off in the
desired manner. Reinforcing the weld will apply to aluminum
the same as every other metal, and a very neat job can be
made after a little practice with the puddle stick. At times
FIG. 77. "Puddle-sticks" for Welding Aluminum.
some of the aluminum may adhere to the stick, which is made
from a quarter-inch piece of steel filler-rod, but this can be
removed by scraping it upon the fire bricks which should be
in the vicinity of the weld.
(121) There are two kinds of filler-rods used in aluminum
welding. Both are aluminum, but one is cast and the other
is 9 drawn rod. This same difference will also be noticed in
bronze filler-rods, and there has been much discussion as to
which is the desirable one to use. Neither of them is sup-
posed to be 100 per cent pure aluminum, as such a filler-rod
does not give the desired results under the action of the
ALUMINUM WELDING 113
flame. A matter of from 90 to 95 per cent aluminum, with
5 per cent to 10 per cent of copper present as an alloy, is found
to make a stronger and more successful weld. It is recom-
mended, if possible, to use the drawn rods whenever avail-
able; for a weld at best is only a casting, and if this casting
can be made from virgin metal, rather than recast from metal
which has been cast many times and the contents not known,
it is thought that the results will be far more satisfactory.
A weld made with such a filler-rod, care being taken to work
out the oxides, will compare very favorably with the strength
of the original metal and in many instances a reinforcement
will make it much stronger.
(122) To combine the two methods of welding aluminum
is not recommended. If the flux were stirred up inside the
weld with a puddle stick an unsatisfactory weld would result,
so they are to be kept entirely separate. It is not necessary
to " V " out aluminum for the same reason as other metals
are " V-ed " out. When it is in workable condition it can be
puddled and stirred about as desired. It is well, however,
to " V" out slightly for the sake of marking the line of weld.
When aluminum is heated up, the expansion which occurs
may close up the crack, which was previously quite visible,
in such a manner that it cannot be located without much
loss of time. Ordinary chalk or soapstone, if available,
may be used to mark any preheated work, but the use of a
chisel along the line of weld is the most reliable method.
PART Two. ALUMINUM WELDING
(123) IT will be noticed, when welding aluminum, that
bright surfaces will oxidize immediately when exposed to the
air. This action occurs perhaps faster on aluminum than on
any other metal. With this oxide or scale present the metal
will not run together nor fuse, no matter how much heat is
114 OXY-ACETYLENE WELDING MANUAL
applied. The metal may be molten on each side of an
oxidized crack and at times will cause the line of fracture to
even float, but if the oxide is not destroyed the metal will
not fuse. As has been noted previously, two methods are
used to destroy this oxide, namely, the flux method and the
puddle system. On account of this exceedingly rapid oxida-
tion, it will be found to the operator's advantage to complete
his aluminum welds as quickly as possible in order that he
will have less of this oxide to combat. It will be found in
using the puddle system that greater haste can be made by
using the torch in the left hand, leaving the right free to do
the puddling and to add whatever metal is necessary. In
this method most of the success depends upon the operator's
skill in handling his puddle stick and puddling in additional
metal. Generally the right hand can do this more rapidly
than the left.
(124) It is well to learn how to make a successful weld
from one side of the metal only, and while this will apply
to all metals, it is especially advantageous in working
aluminum. Where a small layer of metal has been added
to one side of an aluminum job, such as a crank case, and it
does not penetrate the entire thickness of the metal, when the
other side is turned, and the flame applied to it, a difference
in temperature and the loss of strength in this metal when
heated will cause the first side welded to crack unless the
operator is extremely cautious. Therefore it is always well
to learn how to penetrate the entire thickness of the metal
from one side and make a satisfactory weld in this manner.
(125) As previously stated, aluminum when melted
loses most of its strength, and if not supported by some
means or other the metal will collapse. On account of this
it is advisable to back up aluminum work, when possible,
whether the job is to be done cold or in preheated condition.
The most successful manner of backing up is shown in Fig.
78, wherein A represents a thin sheet of copper which has
been fitted to the work, and daubs of asbestos cement shown
at B will aid to some extent in holding the plate in position,
but this alone should not be depended upon. A prop or
fire brick, upon the top of which has been placed a cushion
of cement, will serve as a good backing, but where this cannot
be accomplished filler-rods may be bent in the manner shown
in Fig. 78. These filler-rods are not of the springy type,
but are of soft wire and the loop as shown is not for a spring
FIG. 78. One Method Used to " Back Up " Aluminum Work, when Welding.
A Represents a Sheet of Copper; B, Asbestos Cement.
effect, but merely to take care of the contraction and expan-
sion of the wire. Copper is given a preference over most of
the other sheet metals, because it can be peened with a hammer
to any shape desired, and many odd shaped additions can
be formed by its use.
(126) The use of clamps, when working on aluminum, is
not recommended on account of the great conductivity of
heat and the weakening of the metal as it approaches the
melting-point. Pressure of any kind is not desired and the
116 OXY-ACETYLENE WELDING MANUAL
operators who attempt to use clamps will regret it sooner or
(127) In aluminum work contraction and expansion take
place the same as in other metals, only to a much greater
extent, and greater allowances must be made. However,
the same rules can be applied when determining whether
work should be preheated or not, for if the ends are free to
move, the work can usually be accomplished without pre-
heating, whereas if confined, it will be necessary. When
preheating is necessary the whole piece must be treated in the
same way, regardless of the size. If only part of the work
were preheated and the balance left exposed, it would be almost
impossible to avoid warpage and shrinkage strains, which
would render the work useless. Always preheat the entire
piece if any portion requires it.
(128) Great care must be exercised when setting up alumi-
num work for preheating. Its weight should be distributed
equally on whatever support is used, so that there will be no
danger of any one part sagging, thereby throwing the whole
piece out of alignment. A good way of accomplishing this
is to lay fire bricks on their flat side, in such a manner that the
weight of the work will be fairly well distributed. Then put
a daub of clay or asbestos cement on each brick and press the
aluminum piece down on this cushion. This will overcome
the use of shims and other methods used for jacking up the
work, which are unreliable.
(129) If charcoal is to be used as a preheating fuel, an
oven of fire brick should be built up with draft holes in the
bottom layer of brick, as described in the chapter on Pre-
heating. A layer or two of charcoal is then ignited. The
oven is then covered with asbestos paper or a piece of sheet
metal. Asbestos paper is preferable as the metal becomes
very hot and is apt to burn the operator. After the fire
has received a good start, additional charcoal is added
ALUMINUM WELDING 117
until sufficient heat is obtained. This can be determined by
sprinkling a little sawdust on the surface of the aluminum,
and if it chars readily, the work is ready to weld, Other
methods have been outlined previously, any or all of which
may be used in learning this heat. In executing the weld
as little of the work is exposed to the air as possible, in order
to hold a uniform heat and not permit any part to become
chilled. At the completion of the weld the oven is covered
over, the openings in the bottom row of bricks are stopped
up, and the piece allowed to cool with the dying fire. The
charcoal process is the slow but sure method of handling
preheated aluminum work, and is always recommended.
(130) When preheating aluminum with torches burning
kerosene or gas a different kind of oven is built, as previously
described in the lecture on Preheating. No openings are left
in the lower row of bricks and the oven is built very much
closer to the work being preheated. As the object is to con-
fine as much heat as possible and have a uniform tempera-
ture throughout, it is not desirable to have such ovens loosely
constructed. If the bricks are irregular, a double wall can
be built with a layer of asbestos between them. Such a pro-
cedure is always recommended if time and bricks permit.
A hole is left in one end of the oven for the preheating torch
flame to enter. On aluminum work the flame is never played
directly upon the metal. A baffling plate of metal or fire
brick is used to distribute the flame around the sides of the
piece and very satisfactory results may be obtained by
preheating in this manner.
118 OXY-ACETYLENE WELDING MANUAL
PART THREE. ALUMINUM WELDING
(131) MANY times aluminum crank cases which have large
holes punched in them and parts missing are brought to a
welder for repairs. A question arises as to whether it is best
to back up these holes and fill in the missing parts with a
filler-rod as the welding progresses, or whether these parts
should be cast separately or cut out of another crank case.
It will generally depend upon the size of the hole, as to the
desirable procedure in a case of this kind. It must be re-
membered that if the casting and welding are to be done at
one and the same time each additional layer of metal
must be fused to the last layer and that in reality a great deal
of welding is necessary. In addition this added metal must
be fused to the crank case. On small holes, perhaps two or
three inches in diameter, this method is recommended, but
if the hole is much larger, it is best to cast a piece and then
weld it in, for in this instance there is only one line of weld
to look after.
(132) On aluminum work it is proper to weld from the
closed end of a crack toward the open, whether the piece has
or has not been preheated. This is true also of all other
metals, for if the weld were to be started at the open end and
worked backwards there would certainly be internal strains
set up, which would be undesirable. If it is not clear which
end is the open one, the operator should stop a moment and
figure it out.
(133) Were a suspension arm of the U type on an
aluminum crank case to break about three or four inches from
the body of the case, it could be welded in place without dis-
mantling the motor, if handled properly. Free access must
be had to the line of break, so that the operator can manipu-
late his flame at whatever angle he thinks best. Due to the
contraction and expansion, which may throw the piece being
ALUMINUM WELDING 119
welded out of alignment slightly, it is best to blank the
bolt hole at the end of this suspension arm and face it off,
before the piece is welded in position. Later a new hole can
be drilled which will line up accurately with the frame, and
the welder will not then have to worry or attempt to return
it exactly to its former position. In order to keep the case
itself as cool as possible, wet asbestos should be packed
around it, near the broken arm, so that too much heat will
not be absorbed by it. The broken end is then tacked in
position at two or three places and the weld started. On
such a problem the puddle system will be found best, for both
horizontal and vertical welding are to be done, as well as some
overhead. As flux causes the metal to flow, it is rather
difficult for the beginner to apply it to vertical and over-
head work. The puddle stick should work through the metal
its full thickness and eliminate every possible trace of the
break, digging out the old metal where dirt is found, and adding
new metal for reinforcing. When one side has been welded
and reinforced it should not be allowed to cool while the other
side is being worked. The torch should be played upon it
every now and then, in order that the whole line of weld will
be at approximately the same temperature; otherwise, the
weld may break in cooling. The ease with which aluminum
is puddled together, which many welders have likened to the
children's method of making mud pies, seems so simple to the
beginner that he cannot see where the strength comes from
when cooled. On account of this, he invariably works his
aluminum too long. After welding a few test .bars of this
metal and breaking them in the line of weld, many old welders
will gain confidence upon seeing the results of their own
WELDING OF MALLEABLE IRON
(134) THE welding of malleable iron, so far as the actual
fusion of the metal is concerned, is not practiced except in
very few instances, where the parts are very thin and have
been completely annealed. This is on account of its being
what might be termed a heat-treated metal. To begin with,
malleable iron is cast iron, and becomes malleable only after
FIG. 79. Illustrating Cross-section of Malleable Iron.
it has been heated to the proper condition in the presence of
material which will absorb much of its carbon content, and
kept in this state until a suitable depth of its exterior has
been annealed. It has been changed from a brittle casting
to one which will bend to some extent without breaking, and
its surface, by the withdrawal of the carbon, has been con-
verted into steel. The interior remains cast iron. The
depth of penetration will depend entirely upon the number
WELDING OF MALLEABLE IRON 121
of hours the work is treated. Usually it runs from one-
sixty-fourth to one-eighth of an inch, depending upon the
type of work. An idea may be gained of how a cross-section
of this metal will appear, by noting Fig. 79.
(135) A machinist would not think of destroying the tem-
per in his tools and then attempting to use them without
retempering them. So the welder will not attempt to melt
malleable iron, for he realizes that if he were to attempt fus-
ing this metal that its character would be entirely destroyed.
If he should make a fusion, the weld itself and in the vicinity
thereof the metal would be very brittle and retain none of
its ductile qualities. When- a weld of this kind is attempted,
first, a few steel sparks are given off from the surface of the
metal, which quickly diminish and the surface seems to recede
from the flame. A white foam appears as the steel surface
is burned and many small blow holes then make their appear-
ance. The casting resembles a steel casting which con-
tains much sand and impurities. The welding of malleable
iron, in its broadest sense, is therefore not recommended,
although as it has been stated there are occasions when it
can be successfully accomplished. The best manner of bond-
ing malleable iron is by the use of a bronze filler-rod, and
this process will hereafter be referred to, for convenience,
as welding, although it may resemble brazing in some
(136) The art of welding malleable iron with bronze is
not very difficult to learn. Possibly, the greatest trouble will
be experienced by the beginner in distinguishing malleable
iron from other castings. By again referring to Fig. 43 and
carefully noting the various methods outlined, this trouble
should be overcome. Many times, too, if the welder has
had any mechanical experience, he can probably determine
where the casting has been used and can ofttimes satisfy
himself whether it is malleable or not. Malleable castings
122 OXY-ACETYLENE WELDING MANUAL
are very seldom used as a wearing surface, and are generally
employed where there is strain, to replace steel castings and
forgings, which are much more expensive. If it has been
determined that the metal is malleable iron, half the battle
has been won.
(137) In preparing malleable iron, a clean surface is
necessary in the vicinity of the weld. No " V-ing " out is
necessary unless the piece is greater than one-quarter inch
in thickness, and then the surface of the " V " should be as
rough as possible. The ends are placed as close together as
possible, the same as in brazing, and a welding tip which is
one size smaller than would be used on the same thickness
of cast iron is then used, with a slightly carbonizing flame.
See Fig. 23. The work is heated, the same as in cast iron
and steel. This flame is played directly on the work in a
vertical position, similar to that used in preheating the weld
in cast iron and steel, until heated to a cherry red, back about
one-half inch on each side of the weld. As soon as this heat
is obtained, the bronze filler-rod carries a quantity of bronze
flux to the weld and this further tends to clean the surface.
With the end of the filler-rod directly in contact with the
work nearest the operator, the neutral flame melts the end
of the rod, which immediately should run over the adjoining
surface and through the crack. When this occurs the flame
is abruptly twisted away from that portion of the weld to
avoid burning the bronze. This is repeated along the line
of the weld until the entire surface is covered with a thin
coating of bronze. With this as a foundation more bronze
is added, but during this process the torch is turned so that
the neutral flame will not bear down directly on the bronze,
which has already been added. It should rather strike it at
an angle and radiate enough heat from the side of the neutral
flame to permit a fusion between the filler-rod and the bronze
already added. Much more surface should be covered and
WELDING OF MALLEABLE IRON 123
more of a reinforcement made than in either cast iron or
steel, in order to warrant enough strength for this class of
(138) A good bronze for welding purposes should work
easily under the influence of the oxy-acetylene flame and
have sufficient alloys present to take care of those destroyed
by the action of the flame. It is not thought advisable to
work over welds of bronze, for fear of making them porous,
unless more filler-rod is added whenever the flame is brought
in contact with the weld.
(139) Welds of malleable iron can be made which will
be even stronger than the surrounding metal, and at times
they can be reinforced by adding small strips of steel. These
can be entirely covered, to make them inconspicuous. Con-
trary to custom it is recommended that plenty of flux be used,
for best results have been found when a surplus rather than
a sparing amount has been employed.
(140) The matter of heat in malleable iron is of con-
siderable importance. If not enough heat is used there will
be no fusion between the bronze and the iron, whereas on
the other hand, if too much heat is used, the bronze will not
adhere, but will seem to boil on the surface and form in small
globules rather than spread over the whole metal. In addi-
tion the character of the piece being worked on will be changed
when heated too much. This matter of heat should be given
great attention and the beginner should learn and have em-
phasized the fact that the proper heat is one which will per-
mit the bronze to run like water over the surface, and this
will form a good foundation to work upon.
(141) In general, malleable iron work is seldom preheated,
for this is not necessary if the pieces have been fitted together
as closely as possible before the weld is started. Once the
student has learned the flow of metal and how to reinforce
his weld, he will be in a position to handle most any kind of
124 OXY-ACETYLENE WELDING MANUAL
malleable iron properly. It is well to remember, however,
that malleable iron is allowed to cool slowly and is not
immersed in water, as has been suggested when working on
brass, for here we have one metal in the piece itself and
another in the weld, and too great a strain would set up if
they were cooled abruptly.
(142) BY heating a bar of wrought iron or steel to a
welding heat and holding it in a stream of compressed air,
or a strong blast, it will at once begin to melt and sizzle,
emitting an incandescent and scintillating light. This light
is dangerous to observe at close range without colored glasses.
The burning of the metal can be maintained for hours, without
any other source of heat except that caused by the combus-
tion of the iron. The oxy-acetylene cutting process is based
upon this principle, in that a neutral flame is applied in order
to heat the part being cut to the desired temperature. Once
the melting-point is reached, pure oxygen under pressure is
applied to maintain oxidation and force out the burned
(143) The apparatus used for cutting does not differ
to any great extent from that of the welding class, except that
a different torch is employed. There are combination
regulators and torches manufactured, but a combination tool
is always regarded by most authorities as a loss in efficiency,
either on one side or another. While a low-pressure welding
regulator may be used on the oxygen line for cutting, yet its
use upon large work, where the pressure is high and the regu-
lator must pass a great deal of gas very freely without freezing
up, this low-pressure regulator will be a serious handicap and
cause much trouble, if used.
(144) An ideal arrangement on the oxygen line for cutting
is to have a double or " twin " regulator attached to the oxygen
OXY-ACETYLENE WELDING MANUAL
drum, one side of which will do for welding and the other,
being high-pressure type, will produce a constant flow of
high-pressure gas, suitable for the cutting jet. Then when
cutting is done a three-hose torch should be employed. One
of its oxygen connections which governs the neutral flame
can be connected to the low-pressure regulator, while the
FIG. 80. The Cutting Torch Eats its Way through Steel of any Size with
Remarkable Ease, Leaving a Clean-cut Edge. This View Shows a Cutting
Torch in Operation at the Ordnance Welding School, U. S. Army.
oxygen jet should be controlled by the high-pressure regulator,
the third connection will furnish the acetylene gas for the
preheating flame. However, in place of this three-hose
arrangement, most cutting is accomplished by means of a
two-hose apparatus, wherein only one hose is used to convey
the oxygen from a single regulator to the torch. On such
OXY-ACETYLENE CUTTING 127
apparatus much trouble is usually experienced in cutting
old metals where a great deal of scale is present or in a close
place where the torch is apt to get hot.
(145) Many times part of the scale or metal will pop
up against the tip and cause the oxygen jet to flicker. This
slight variation may cause an excessive pressure of oxygen
to be introduced into the preheating flame momentarily,
by backing up the oxygen in the cutting jet. This lean
mixture of gas will generally flash back instantaneously and
will deposit a layer of carbon on the inside of the tip, which
causes much annoyance to the operator. This condition is
to be found where there is but one oxygen line. In the two-
hose arrangement this is entirely overcome, due to the
independence of the pressure on each line.
(146) The high-pressure regulator differs from the low-
pressure regulator in these respects: The diaphragm, see
Fig. 1 6, is much smaller in diameter, which makes it less
sensitive, and of course much stronger. The diaphragm
springs are usually much heavier; the nozzle contains a
larger opening for passing gas freely without freezing; and
to take care of the increased pressure on the line, usually a
higher pressure working gauge is added to the regulator.
Such a regulator is capable of passing much more gas than
the low-pressure type, but as far as being as sensitive and
maintaining a constant, absolute flow of gas, its design will
not permit it to do so. In cutting, these requisites are not
necessary. In welding, however, the delicate adjustment of
the flame demands a very sensitive regulator and usually
the larger the diameter of the diaphragm the more sensi-
tive the adjustment.
(147) The cutting torch differs from the welding torch
in many respects. The tip itself, when looking at its end,
may resemble any one of the views shown in Fig. 81. In
the welding torch, but one hole is to be found in the tip;
128 OXY-ACETYLENE WELDING MANUAL
in the cutting tips, two or more holes are to be found. In
all cases the center hole passes pure oxygen, whereas in the
surrounding holes, both oxygen and acetylene mix and when
lighted give a neutral flame. This will hereafter be called
the preheating flame. The gases issuing from these openings
are controlled by three valves, one of which may have a
trigger or lever arrangement for quick action, and it will
control the center jet of oxygen which really does the cutting.
This is under much higher pressure than the preheating
flame. The other two valves will control the oxygen and
FIG. 81. End Views of Cutting Tips, Showing Possible Arrangements of
Preheating Flames in Regard to Oxygen Jet. The Black Circles Repre-
sent the Preheating Flames, which Vary in Number and Arrangement
According to the Nature of the Work, the Possible Limit being a Con-
tinuous Circle, as Shown. The White Circles Illustrates the Oxygen
Jet, which, too, Varies in Size According to the Work.
acetylene gases used for the preheating flame. In lighting
such a torch, the acetylene is turned on in the same manner
as has been taught when welding, until it just leaves the end of
the tip. Then the oxygen valve is opened, which controls
the preheating flame, and enough is permitted to pass to
produce a neutral flame. As soon as this has been accom-
plished, the third valve should be quickly opened and held
so a moment, to see if the neutral flame has been changed.
Generally this operation will deprive the neutral flame of
some of its oxygen, and a feather flame, showing too much
acetylene and not enough oxygen gas, can be noticed. This
will necessitate turning on slightly more oxygen at the torch
valve. The third valve is then shut off and the torch is ready
to start cutting.
(148) On small cutting jobs, about as much acetylene
(Courtesy of the General Welding & Equipment Co.)
FIG. 82. Cutting a Heavy Shaft.
pressure is used on the line as there would be if it were a
welding job. The oxygen pressure, however, is generally
much greater, and a pressure anywhere from ten to two
130 OXY-ACETYLENE WELDING MANUAL
hundred pounds should be used, depending upon the thick-
ness of the metal and the conditions which must be met.
In extreme cases where very heavy cuts are to be made, a
much higher pressure than has been mentioned should be
used, but the limitations given will cover a wide range of
work. To start a cut it is necessary to bring the preheating
flame in contact with one edge of the metal to be cut and play
it there until the metal is red hot. As soon as this condition
is reached the torch is held steady the neutral flame
just touching the metal; then the third valve controlling
the cutting jet of oxygen is opened. This oxygen, under high
FIG. 83. Position to Hold Torch in when Cutting Metal.
pressure, quickly acts upon the hot metal and severs it instan-
taneously, melting and oxidizing the metal so that it will not
flow together, in one and the same operation. As soon as
this occurs the torch should be advanced as rapidly as possible
in the direction the metal is to be cut. The more rapid the
advancement and the steadier the torch is held the cleaner
the cut will be; and incidentally, less gas consumed in the
execution of the job. In cutting, as in welding, it is always
well to give the torch a chance, and when the operator sees
much molten metal splashing directly back on the torch, he
should change the angle slightly to avoid his apparatus
becoming overheated. It has been found that if the cutting
OXY-ACETYLENE CUTTING 131
torch is held at the angle shown in Fig. 83, the most satisfac-
tory results can be expected.
(149) At the present time only such metals as steel and
wrought iron can be successfully cut. When it comes to
cast iron no method has yet been discovered to cut it with
any degree of success by the oxy-acetylene flame, on account
of the high melting-point of the oxide and various other mat-
ters. The day is looked forward to, however, when after
sufficient time and study has been devoted to this subject,
FIG. 84. Method of Cutting with Two Welding Torches. Torch A is Adjusted
so that a Neutral Flame will do the Preheating, while a Fork in the Oxygen
Line Supplies Oxygen only to Torch B, and it does the Cutting.
that cast iron can be as successfully cut as any other metal,
by introducing another gas or agent to destroy some of
the reactions which retard its application at the present
(150) The use of the cutting torch in preparing steel
work, for welding of large size, plays an important part, in
quickly and efficiently " V-ing" out and getting it ready for
use. Care should be taken, after its use, to see that the
heavy oxide which it leaves is largely destroyed, before any
more metal is added.
132 OXY-ACETYLENE WELDING MANUAL
(151) Frequently the welder has a call for a cutting
torch, where none is available, yet an extra welding torch
or two may be on hand. If this is the case, two welding
torches may be fastened together in such a manner that a
temporary job of cutting may be handled. The arrange-
ment shown in Fig. 84 illustrates this point. If no extra
welding torch is available, a carbon burning torch or any piece
of copper tubing which has a valve in one end, suitable for
taking a hose connection, and the other end free to have a
welding tip brazed on, can be used in the same manner. The
welding torch will give the neutral flame and the extra line
of oxygen will do the cutting. It is well to remember that
FIG. 85. When no Edge is Available to Start the Cut on Large Work, Much
Time may be Saved by Making a Curl with a Cold Chisel, as Shown.
oxygen, no matter under what pressure, cannot be expected
to act upon cold metal. A red heat is absolutely necessary.
There are various short cuts, it is true, in obtaining this heat,
and where a large shaft is to be cut, the operator would not
think of playing his torch upon such a piece of metal until
it was red hot in the locality in which he wished to start
his cut. This would consume too much time and gas. Gen-
erally a hammer and cold chisel are brought into play and a
slight curl on the metal is obtained as shown in Fig. 85.
The moment this becomes red hot, the oxygen jet may be
turned on, and the cut commenced. As soon as started, the
operator is able to " carry-on " at will,
OXY-ACETYLENE CUTTING 133
(152) An armored hose is generally used on the oxygen
line for cutting, as well as on the acetylene line, as there is
much more pressure used in cutting than in welding. This
type of hose wears much longer and does not kink to the extent
that the unprotected hose does. The armor protects both
lines from being burned by the melted metal, which is very
apt to come in contact with the rubber, were it not protected'
in some manner.
(153) The question often arises in welding circles, as
to why, since the cutting torch contains a series of neutral
flames, it would not be just as well to use such a method in
welding, as no doubt more heat could be obtained and a greater
surface handled. The answer to such a question would be,
that the opportunity for oxidation is so great that successful
welding could not be expected, although if this were the last
means at a welder's disposal, he would certainly be justified
in making a weld in this manner. He should be very careful,
however, to see that his extra oxygen supply is completely
shut off and that there is no possible chance for that gas
leaking into the weld.
(154) To plunge a flame, such as is used in the cutting
torch, under water and see it continue to burn while sub-
merged, looks quite marvelous to the average layman. Yet in
cutting piling along water fronts this is continually being done.
Not only does the torch stay lighted, but it retains much
of its efficiency as a cutting tool, and some instances have been
recorded where cutting has been accomplished at a depth of
thirty feet under the sea. It is true that the water conducts
a large part of the heat away very rapidly, but to facilitate
such operations, an air line is brought down which ejects
air under the torch and clears the water away to some extent,
but this is not necessary. In order to explain this phenomenon
in a very simple way, it will be stated that nothing will burn
unless oxygen is present, and the more oxygen used, up to a
134 OXY-ACETYLENE WELDING MANUAL
certain point, the more rapidly will the burning take place.
When submerging the cutting torch, it is presumed that the
flame obtains what added oxygen is necessary from the cut-
ting jet and this together with the velocity of the flame and
its hydrogen enveloping flame permits the neutral flame
to continue burning.
(155) THOSE who are familiar with gasoline engines will
know that after being used for some time, the impurities in
FIG. 86. Removing Carbon from U. S. Army Truck, by the Oxygen Process,
at the Ordnance Welding School.
the lubrication oil and in the gasoline, which is continually
being burned, will form around the top of the piston and
cylinder head in the motor. When enough has been deposited
136 OXY-ACETYLENE WELDING MANUAL
and a few high points become overheated through long run-
ning, there will be a metallic knock distinctly heard when an
extra strain is being exerted by the motor. This layer
of impurities is called carbon and its presence means loss of
power. Owing to the construction of most cylinder blocks,
it is a very difficult matter to reach this portion of the block
without dismantling. This requires skilled labor and means
much delay. A method of removing this carbon by the oxy-
gen process has been devised, which will save much time and
(156) To remove carbon from a gasoline engine, first
shut off the gasoline in the line and allow the engine to run
until all gas has been removed from the carburetor. This
is merely a safety measure. If a vacuum feed is used, the
vacuum tank is drained, as it would require much time for the
engine to consume this amount of gas. The hood of the car
is then removed and all parts of the motor on the side where
the burning is to be done are covered with asbestos paper
or by a heavy piece of canvas which has previously been
dampened. This is to keep the sparks from dropping into
the apron or oily parts of the machine. Remove the spark
plugs and see from the condition of these spark plugs whether
the cylinder is dry or oily. An oily cylinder will burn out
much more rapidly than when dry. This can be detected
very easily from the condition of the spark plugs. It is
recommended that only the spark plugs be removed as the
removal of the bonnet or any larger portion will require
much more oxygen and will not produce as satisfactory
results as when the oxygen is introduced through a small
(157) Place the carbon removing apparatus, which con-
sists of the oxygen drum, regulator, a length of hose and
carbon burning torch, the latter being made up principally
of a shut-off valve and a long length of small copper tubing
as shown at A in Fig. 87 . Turn on not over twenty-five pounds
oxygen pressure as far as the torch, and the apparatus is then
ready to use. With the torch inserted through the spark
plug hole in number one cylinder, that is, the one nearest
the radiator, guide the rise of the piston until it is at the top
of the stroke. This means that both intake and exhaust
valves are closed. On automobiles where a self starter is
used, it will be necessary to use a crank
for turning over the motor. With the
piston at the top of the stroke and both
valves closed, there is only a small
portion of the cylinder head to be
worked upon and this is the part which
has the carbon deposit upon it. All
machined surfaces and valve seats are
fully protected and will not be subjected
to any exposure during the burning. If
the cylinder seems very dry, a teaspoon
of alcohol or kerosene may be sprayed
into it through the spark plug port, to
facilitate the clearing of the carbon. If
the cylinder is somewhat oily, this is
not necessary. A match or burning
taper is then held over the hole and a
stream of oxygen will carry the flame
down into the cylinder and ignite the
carbon. As soon as this occurs, a
small cracking noise can be heard and the carbon will run
around the inside of the cylinder in a heated condition. The
part around the valves should be cleaned of! first, before
going to the inner chamber, as this process does not seem to
work very well if performed the other way. A roaring noise
will be in evidence and the popping of the carbon from
the surface as it frees itself may frighten the operator
FIG. 87. Carbon Burn-
ing Apparatus. The
Small Copper Tube A
is Flexible and can be
Bent in any Shape
138 OXY-ACETYLENE WELDING MANUAL
when attempting his first job, but there is absolutely no
(158) It must be remembered that oxygen itself does not
burn, but merely assists the other inflammable material in
burning, therefore it is only the carbon which is contained
in the cylinder that in this case does the burning. As soon
as this is all consumed, there will be nothing else to burn and
the sparks will die of their own accord. When this occurs,
the operator will shut off his torch, blow the cylinder out
with compressed air and replace the spark plug and then
proceed with the next cylinder, which he will treat in the
same manner. He must be sure, however, that the piston
in cylinder number two, or whatever cylinder he is working
on, is moved to the top of its stroke and that both valves in
that particular cylinder are closed before he starts his burn-
ing. After all cylinders have been treated like number one
and the spark plugs are in position, the gasoline is turned on
(if the vacuum tank has been drained, it is best to fill this),
and the motor started, with the exhaust " cut off " open,
in order that any loose particles of carbon may be blown out.
(159) While this process is in very common use, and
seems to be very simple, there are many who go through
the steps without obtaining satisfactory results. It is con-
sidered best, if possible, in attempting carbon burning for the
first time, to try it on some motor which is about to be over-
hauled, in order that the results may be studied so that the
operator will not go blindly on, without showing some im-
provement. Many times only the high points are burned
out, which will free the motor temporarily of some of its
knocks, but within a week or so they will become evident
again. He who will become proficient in learning carbon
burning should apply himself and study his results.
(160) There are those who consider carbon burning in-
jurious to the motor on account of the high temperature flame
CARBON BURNING 139
which they think is introduced. But it is ignorance as to
the working principle of this process that makes them think
this. When it is considered that a gasoline motor depends
upon a rapid succession of internal explosions for its power,
the folly of condemning a process of this nature, where abso-
lutely no actual flame is used, will be seen. It is only the
incandescent particles of carbon flying about that give any
heat at all. After a cylinder has been burned or decarbonized,
the hand can be placed upon it immediately, without any
fear of being burned. Those motors equipped with aluminum
pistons may be handled in the same way as those of cast
iron, and when properly used this method of decarbonization
is very satisfactory.
(161) Many times it is asked how often carbon burning
is to be recommended. This will all depend upon the type
of motor, its condition, and to some extent, upon the lubri-
cating oil and gasoline used, as well as the mileage of the car.
If a machine is being run continually, it may be necessary
to have the carbon removed about every two months, but
conditions will ter i to lengthen or shorten this time as the
case may be. When the knocks are in evidence, and the
loss of power is noticed, it is time for the carbon to be re-
moved, and whether this is one month or two it is an error
to continue running the car which is filled with carbon.
Invariably the carbon burner is asked by his customer whether
carbon burning will regrind valves; this and many other
questions can be intelligently answered and explained to the
questioner's satisfaction if a careful study of the process is
(162) In drawing this elementary course in oxy-acetylene
welding to a close, the author wishes to again call attention
to the fact that this course is merely to be considered as a
OXY-ACETYLENE WELDING MANUAL
(Courtesy of the British Oxygen Co.)
FIG. 88. Photograph Showing Square Piece Cut Out of a Steel Block 9 Inches
(Courtesy of the Dains-P.ournonmlle Co.)
FIG. 89. This is an Electrically Driven Oxy-acetylene Cutting Machine
for Making Duplicate Cuts on Steel from a Drawing. Dies and many
Irregular Forms may be Produced at Low Cost by it.
foundation upon which to build. An effort has been made to
confine the student's line of thought exclusively to the actual
welding of the various metals and an intimate knowledge of
the tools necessary to accomplish this. Technical terms have
been avoided as much as possible, and history, as well as the
(Courtesy of the Dams-Bournonville Co.)
FIG. 90. This Shows a Motor-driven Oxy-acetylene Device Particularly
Adapted to Cutting Plates or Sheets into Round, Oval, or Irregular Forms
with either Straight or Beveled Edges.
generation of the various gases, have been considered only of
secondary importance and have been purposely omitted.
Many repetitions have been made to place emphasis upon
certain points and methods. It is hoped that the student
who pursues this course if he has been restricted to the use
OXY-ACETYLENE WELDING MANUAL
of only one apparatus will realize that there are many
such on the market, each one of which may have its advan-
tages, but if the general rules, as outlined, are followed, he
will not have much difficulty or be covered with confusion
if called upon to operate different makes of apparatus for
FIG. 91. Quick, Permanent Repairs are Made on Large Supply Trucks in
the U. S. Army by its Corps of Trained Welders. This View Shows an
Individual Welding Unit in Operation at the U. S. Army (Ordnance)
the first time. If he sees that there is gas pressure on his
lines, he should not hesitate, thereby showing his ignorance
of that particular type of apparatus, rather let him turn on
one valve, and direct the stream of gas toward his nostrils.
He can then readily determine whether it is the fuel gas or
not and knowing that oxygen will not burn he can turn his
(Courtesy of Ben K. Smith, V. S. Welding Co.)
FIG. 92. This Cylinder did not Require to be Bored or have any other
Machine Work Performed, but was Placed in Service Directly after
Welding and has been Serving for over Three Years.
144 OXY-ACETYLENE WELDING MANUAL
fuel gas on and proceed without showing any concern. It
might be said that confidence in one's self is the keynote of
success, and this is imperative to make an expert welder,
but to the man who studies the flame action on his metals
and appreciates the apparatus to the fullest extent, there is a
very bright future.
(163) The welder who desires the best results should
procure the best apparatus possible to fill his requirements.
The cost of such is only of secondary importance, the hazard
attached to cheaply constructed apparatus and the loss of
gas, time and the execution of faulty work and the depre-
ciation of the welder's reputation, are matters of vital im-
portance. The supplies too, such as filler-rods and the like,
should be obtained only from reliable welding companies
who have their own shops in which they may test them. It
is false economy indeed, to attempt to save a few cents on
filling materials, for many dollars' worth of time and gas
may be lost on account of the failure of the metal added.
(164) There are a few illustrations set forth herein, to
show what has been accomplished in the way of machine
construction used in adapting the oxy-acetylene process to
the requirements of various manufacturers. These will tend
to show to some extent what the future has in store for this
(165) It has been rightly stated that oxy-acetylene
welding is yet in its infancy. The torches, regulators and in
fact all parts of the apparatus are constantly being improved.
The process of cutting cast iron must still be solved, so it
will again be stated that it behooves those who are interested
in this work to apply themselves to the great future in store
DEFINITIONS OF TERMS AND WORDS APPLIED TO OXY-
ACETYLENE WELDING AND CUTTING
ACETONE. A liquid which is capable of absorbing twenty-five times
its volume of acetylene gas under normal temperature and pressure.
Employed as a solvent in the acetylene cylinder.
ACETYLENE. An inflammable gas used for welding and cutting.
ACETYLENE CYLINDER. A steel tank filled with porous material
and acetone, in which acetylene gas is stored.
ADAPTER. A brass fitting used to connect regulators to different
ALIGNMENT. State of being in line.
ALLOY. Metal which is added to another metal. A mixture of two
or more entirely different metals.
ANGLE IRON. A steel bar, the cross-section of which forms an angle
of 90 degrees.
ASBESTOS. A fibrous material not affected by fire. Usually supplied
in sheets or shredded.
AUTOGENOUS WELDING. The process of uniting two pieces of metal
together by fusing without additional metal being added, and without
the aid of hammering.
BABBITTED. Lined with Babbitt metal. Generally found in bear-
BACK FIRE. The popping out of the torch flame, due to a slight
explosion of the mixed gas between the torch tip and the mixing chamber.
BEARING. Support or wearing surface for a revolving shaft.
BEVEL. To cut or form at an angle.
BEVELED EDGE. An edge cut or formed at an angle.
BLOWHOLE. A hole or cavity formed by trapped gas in metal.
BLOWPIPE. A torch which mixes and burns gases producing high-
temperature flames. The term TORCH is given preference in oxy-acety-
lene welding and cutting.
BRAZING. Uniting metals with brass or bronze by means of heat.
BRAZING WIRE. A filler-rod of brass or bronze used in brazing.
BUTT JOINT. A joint made by butting two edges together.
CAP. A metal cover used to protect cylinder valves.
CARBON BLOCKS. Carbon in block form. Used to assist in building
up parts that are to be added. They may be ground to any shape
CARBON RODS. Carbon in rod form. Employed to save holes
around which the metal is melted.
CARBONIZING FLAME. A flame with an excess of acetylene gas.
CONTRACTION. The shrinkage of metal due to cooling.
CROSS-BAR. Hand screw for adjusting the passage of gas through
CUTTING JET. Central jet of oxygen issuing from tip of cutting
CUTTING TORCH. A torch with one or more heating jets and an
oxygen jet, used for cutting metals in the oxy-acetylene process.
CYLINDER. A tank containing gas under pressure.
DUCTILE. That property which permits metal being formed or
drawn into different shapes without breaking.
EXPANSION. Increase in size due to heating.
FILLER-ROD. A rod or wire used to supply additional metal to the
FILLET WELD. A weld made in a corner.
FLAME PROPAGATION. The rate at which a flame will travel.
FLASH BACK. The burning back of the gases to the mixing chamber
or possibly farther.
FLUX. Chemical powder used to dissolve the oxides and clean
the metal when welding.
GAS. Erroneously applied to acetylene gas alone. Both oxygen
and acetylene are in the form of gas.
GAUGE. An instrument for measuring pressures of gases.
GENERATOR. A device for manufacturing gas. Usually specified
as acetylene generator or oxygen generator.
GRAIN. The arrangement of the molecules or crystals which make
up a metal.
HORIZONTAL WELDING. Welding in a level position.
I-BEAM. A steel bar with the cross-section of an I. Sometimes
called EYE BEAM.
LINE. Hose or pipe carrying gas.
MANIFOLD. A header with outlets or branches by which several
cylinders of gas may be used in batteries.
MONEL METAL. An alloy of copper and nickel.
NIPPLE. A short piece of pipe.
OVERHEAD WELDING. Welding with the torch overhead.
OXIDATION. A combination with oxygen.
OXIDE. A coating or scale formed by oxygen combining with metal.
OXIDIZING FLAME. A flame with an excess of oxygen gas.
OXYGEN. A non-inflammable gas used in oxy-acetylene welding
OXYGEN CYLINDER. A steel tank for storing and shipping oxygen.
Available for commercial work in 100, 200, and 250 cubic-foot sizes.
The oxygen is compressed as free gas to 1800 pounds .pressure at 68
PEENING. Stretching the surface of cold metal by use of the hammer.
PENETRATION. A thorough welding completely through the joint
of the pieces or parts being fused.
PREHEATING. The heating of a metal part previous to welding.
Generally used to prevent strains or distortion from contraction and
expansion; also to save gas.
POOL. A small body of molten metal formed by the torch flame.
PUDDLE STICK. A steel rod flattened at one end, used to break up
oxides, remove dirt and build up additional metal. Particularly help-
ful in welding cast aluminum.
PUDDLING. The manipulation of the filler-rod or the puddle-stick
in such a manner as to break up oxides, remove dirt, and aid in securing
a good fusion of the metal.
REDUCING FLAME. (See Carbonizing Flame.)
REDUCING VALVE. (See Regulator.)
REGULATOR. A device for reducing and maintaining a uniform
pressure of gas from cylinders, generators or shop lines.
SCALE. A coating of oxide on fused iron or steel that breaks off as
the metal cools.
SCALING POWDER. A name given flux.
SLAG. The oxidized metal and scale blown out when cutting.
SOLDERING. Uniting metals by fusing with a different metal which
has a much lower melting-point than the pieces to be joined. The use
of a lead, tin and zinc alloy is called soft soldering. Hard soldering is
similar to brazing.
TACKING. Fusing pieces together at one or more places.
TIP. A copper or brass nozzle for a welding or cutting torch.
V. Angle or groove between two beveled edges prepared for welding.
V-BLOCK. Block cut out in the shape of a V, or angle iron, used in
lining up shafts.
VALVE. A device for shutting off the passage of gas.
VERTICAL WELDING. Welding as applied to an upright position.
WELDING ROD. Material used to supply additional metal to the
weld. (See Filler-rod.)
NOTE. In order to determine whether the student is obtaining
the information desired it is sometimes thought fitting to give written
examinations. These serve as an index as to what the student has
learned and what he has not. They also let the instructor know
whether he is making every point clear in his training.
The following questions fit in with each chapter or part thereof
and are merely a suggestion for the instructor who has no course of
training outlined. With one or two exceptions all answers to these
questions may be found within the manual. There are a few mislead-
ing questions purposely inserted to see if the student is thinking for
LECTURE NUMBER ONE
1. Name the different classes into which oxy -acetylene welding
paratus may be divided and explain the principles upon which this
2. Illustrate by line sketches the various locations of the mixing
chambers for the oxygen and acetylene gases in welding torches.
3. (a) Where is the logical location for the mixing chamber in
welding torches employed in automobile and tractor repair work?
(6) Give reasons for so thinking.
4. How is the torch and the welding tips treated after repeated
"flash-backs" have taken place?
5. Describe briefly the working principles of a regulator and illus-
trate with a simple sketch.
6. Explain the difference between high and low-pressure regulators.
7. (a) Can acetylene regulators be interchanged with oxygen
regulators with perfect safety? Explain why.
(6) How is it possible, in majority of cases, to distinguish in a very
simple manner, between oxygen and acetylene regulators, when no
gauges are attached?
(c) Why does this difference exist?
8. (a) Why should all tension upon diaphragm springs be removed
before admitting gas under pressure to the regulator?
(b) Can a regulator which has been abused in this manner be
(c) What can be employed as a fitting substitute for gallilith?
9. Explain why the high-pressure gauge on the acetylene regulator
cannot be used as an index to the contents of the attached cylinder of
gas in exactly the same manner as the oxygen high-pressure gauge.
10. Why is glycerine used as a substitute for oil when regrinding
torch valve-seats with emery powder, and with lead-oxide in the
caulking of leaky joints along the line?
LECTURE NUMBER TWO
1. (a) Under what pressure is oxygen gas received in the cylinders
(b) Does this pressure vary to any great extent with changes in
2. (a) Under what pressure is acetylene gas received in the cylinders
(b} Does this pressure vary to any great extent with changes in
3 (a) In setting-up apparatus for the first time, or in attaching
regulators to new cylinders, what precaution should be observed
regarding cross-bar on regulators before the gas is turned on?
(6) Where should the operator stand when turning on the gas?
4. (a) How much pressure should be placed on the oxygen hose,
when the torch-valves are closed, before starting to operate with a
(b) How much pressure should be placed on the acetylene hose,
when the torch-valves are closed, before starting to operate with a
5. (a) After both the oxygen and acetylene gases are in the line
hoses as far as the torch, which valve on the torch is opened first in order
(b} What would happen if the other torch-valve were opened first?
(c) What would likely occur if both valves were opened before torch
6. (a) How is it possible, when lighting torch, to determine whethe
enough pressure is on the acetylene line without looking at gauge?
(b) How is it possible, in the case of oxygen pressure?
7. (a) What is meant by a neutral flame?
(b) How hot is a neutral oxy-acetylene flame?
(c) Is the temperature of a neutral flame the same whether large or
small tip is used?
8. (a) If too much acetylene gas is used, how will the flame be
(b) What action will this have on the weld?
9. (a) If too much oxygen gas is used, how will the flame be affected?
(b) What action will this have on the weld?
10. (a) Explain briefly how apparatus is shut-off, when not to be
used for several hours or more.
(b) Why should particular care be taken to see that acetylene cyl-
inders are tightly closed when empty?
(c) What action does oxygen have on oils and greases?
LECTURE NUMBER THREE
Subject WELDING OF CAST IRON
1. (a) How is it possible to distinguish cast iron from such metals
as malleable iron?
(b) From semi-cast iron?
(c) From cast steel?
2. (a) What kind metal is used in making "filler-rod" used in the
welding of cast iron?
(b) What general rule can be laid down as to the relation of the metal
in the "filler-rod" to the metal to be welded?
3. (a) What are the characteristics of good cast iron "filler-rods"?
(b) Can piston rings and other small scraps of cast iron be used
successfully as "filler-rods"? Explain why.
4. (a) What is the purpose of a flux?
(b) Is a flux used in the welding of cast iron?
5. (a) Name one formula for making a cast-iron flux?
(b) How often is the flux applied, and by what means?
(c) In what condition are fluxes kept when not in use?
6. (a) How should the flame be held in the welding of all cast iron?
(b) When and how is the "filler-rod" added to the weld?
7. (a) Name the one principal cause of blow-holes and hard spots
in the weld.
(b) Mention some of the others.
8. (a) When is it advisable to grind, or " V " out, the ends of the pieces
to be welded?
(b) When is it not advisable?
9. (a) Does the application of heat cause contraction or expansion in
(6) Are there any excepts to this rule? Name one.
10. (a) Were two cast-iron bars measuring 2X12 inches and ^-inch
thick, to be welded, end to end, what precaution should be observed in
laying out, if the finished job is to measure just 24 inches long?
(b} In what respect would this problem differ were the bars only 6
inches originally and the finished job to measure 12 inches overall?
(c) Is the action of the metal in the weld a constant, or a variable
quantity depending upon the length of the bar in this problem?
LECTURE NUMBER FOUR
Subject WELDING OF CAST IRON
11. (a) How could a spoke, broken midway between the hub and rim,
of a 24-inch, 4-spoke wheel (otherwise intact) be welded without pre-
heating? (Use a sketch if necessary to make method clear.)
(b) If a wheel of like size were broken only in the rim, midway
between spokes, explain procedure in welding without preheating.
(c) Same sized wheel, broken only in hub; can weld be made without
preheating? Give reasons for so thinking.
(d) Were breaks (a), (b) and (c} all present in same wheel, with rim
fracture on opposite side of adjoining spoke from break in hub, should
welding be started at rim or hub? Why?
12. (a) In the building up of broken or missing teeth in cast-iron
gears, what procedure is necessary when no carbon blocks are available
(b) If certain carbon centers from dry cell batteries are obtainable
how should they be treated before allowing molten metal to come in
direct contact with them?
(c) What very important point must be uppermost in mind when
dental work on gears is being done?
(d) Explain precautions taken in allowing work of this nature to cool.
13. .(a) Realizing that hard spots occur in most welds executed by
the new welder and having learned the cause of their presence and
how to overcome them, would it not be possible to utilize this process
for hardening parts which were subject to much wear and little
strain? Explain procedure.
(b) Why is it necessary to preheat such pieces as the following before
the weld is attempted; broken water-jackets on gas-engine cylinders,
usually brought about by freezing, and holes or cracks in crank
cases, caused by the loosening of a connection rod; when lugs on the same
cylinder, the arms on the same crank case can be welded without pre-
heating, and ofttimes without even dismantling the motor?
LECTURE NUMBER FIVE
Subject WELDING OF CAST IRON
14. Describe fully the manner in which two cast-iron bars measuring
i X6 inches and 24 inches long, are welded end to end, citing preparations,
precautions, and the procedure and materials necessary to execute and
carry the weld through to a cool state.
NOTE. Both gases are in the line hoses as far as the welding torch.
LECTURE NUMBER SIX
Subject WELDING or CAST IRON
15. (a) Are water jackets on cast-iron cylinder blocks welded in a
cold, or a preheated condition?
(b) Is this true under all conditions?
(c) If a crack were found in the combustion head of a cylinder block
and the entire water jacket and cylinder were cast in one, how should this
job be prepared in order to make a successful weld?
(d) In welding a broken lug on the base of a cylinder block how should
lug appear after weld is cold?
LECTURE NUMBER SEVEN
1. Describe the operation, step by step, taken to set up an oxy-
acetylene welding plant, from the assembling of the parts, right through,
until a neutral welding flame is obtained. (If a sketch, with the gas
cylinders and parts numbered i, 2, 3, etc., will assist in making descrip-
tion clear, it may be used.)
2. (a) Is it desirable to have a planed metal, or a brick-top table for
(6) Explain why.
3. Outline and describe briefly, a simple method of building a popular
type of welding table.
4. (a) What is the name and style of bricks used in the welding shop?
(b) Name at least three purposes for which these bricks are used.
5. (a) Why does an emery wheel play such an important part in the
oxy-acetylene welding industry?
(b) Why is it desirable to have a flexible shaft attachment for the
emery wheel, if possible?
(c) Name some of the important things a flexible shaft attachment
is used for in the preparation and finishing of welds.
6. (a) In what kind of containers is retort cement purchased in the
(b) Where is retort cement used in the welding shop?
(c) How does it differ from the ordinary clay or putty?
7. (a) Why should a blacksmith forge be added to the welding
shop equipment if one is obtainable?
(b) What two important tasks is a forge used for in the welding
8. (a) It is essential that several pails of water be located throughout
the shop; why should this be necessary?
(b) Mention a few instances where water is required in the welding
9. Explain fully why great care should be exercised in ventilating a
shop where commercial welding is being done.
10. (a) Describe one simple method of constructing a flux box.
(b) What advantages has this type of container?
LECTURE NUMBER EIGHT
1. What is the best method of locating a leak in either the oxygen or
2. If a leak were found in a ground seat, how could it be stopped if
the nut on the coupling had been screwed up as far as possible?
3. Name one method of attaching connections to hoses so that tkey
will not blow off or pull off when pressure is applied.
4. How could either an oxygen or acetylene hose that had been
burned or otherwise injured, be repaired to withstand the gas pressure?
5. How could regulator be operated if the cross-bar for applying pres-
sure upon the diaphragm springs were lost?
6. (a) What procedure would be necessary to make connection if
cylinder were supplied with an adaptor which would not fit the regulator
connection and it could not be coupled up directly?
(b) Realizing that all cylinder connections about a regulator are gen-
erally supplied with a ^-inch taper pipe thread, why do all manufacturers
solder them in?
7. Explain why oxygen high-pressure gauges are constructed with a
loose back and a solid front.
8. (a) Where is the first place to seek trouble in a gauge if it leaks?
(b) Can such leaks be repaired?
(c) Describe method.
9. If either a high- or low-pressure gauge were injured beyond the
repair state how could welding plant be kept in operation without it?
10. (a) What would be the trouble, in shutting off a welding plant,
if there were a reading on the high-pressure gauge and none on the low-
pressure gauge, after permitting gas to escape from the hose?
(b) How could the reading on this gauge be brought back to zero?
LECTURE NUMBER NINE
Subject STEEL WELDING
1. (a) Is the welding of steel more or less difficult than cast iron?
(b) Explain why.
2. (a) Why is the choice of the welding tip so important when working
(b) What will result if the tip is too large?
(c) If too small?
3. (a) Why is the choice of a "filler-rod" of a correct size so impor-
tant for steel welding?
(b) What will happen if the "filler-rod" is too large?
(c) If too small?
4. (a) What kind of a "filler-rod" is used in welding steel?
(b) Give a general rule covering relation of "filler-rod" to the metal
being welded in all cases, but one or two.
(c) Name one exception.
5. (a) Is a flux (or scaling powder) necessary in welding steel?
(b) Explain why.
6. (a) How is the flame adjusted for steel welding?
(b) What kind of a flame is generally used in finishing steel work?
(c) Why is this done?
7. (a) How is the flame held when executing a steel weld?
(6) How is the "filler-rod" held when making a steel weld?
8. (a) Is it necessary to "V" out on steel the same as on cast iron?
(b) Explain why.
9. (a) Is a steel weld as strong as the original metal if not built up?
(b) Explain why.
10. (a) Is the same provision made for expansion and contraction
on steel as on cast iron?
(b) Give reasons for so thmking.
LECTURE NUMBER TEN
Subject STEEL WELDING
11. (a) What is meant by a "crater" in steel welding?
(6) How are they removed from the weld?
12. (a) What are some methods and marks of distinguishing steel
from other metals?
(b) How is cast steel distinguished from cast iron?
13. (a) Name some of the qualifications of a good "filler-rod" for
mild steel welding.
(b) In what manner does the "filler-rod" differ for the alloyed and
14. (a) In bringing the neutral flame in contact with the metal on a
steel weld, should the cone bend and spread on the surface, or just
(b) Explain why.
15. (a) What is the principal cause for hard spots in steel welds?
(b) What causes some of the others?
16. (a) Is it rolled steel or cast steel that does not expand when
(b) Name one other metal that does not expand when heated.
17. (a) Why are welds more difficult on sheet iron and steel than on
some of the heavier pieces?
(b) What can be used as a "filler-rod" on sheet metal work?
18. (a) What difficulty is generally encountered, when making a
long weld like on a steel tank?
(b) How can this be overcome?
(c) Why do the open ends on sheet steel welds overlap in welding
when same class of work on cast iron separates?
19. (a) What causes steel welds to carbonize?
(6) What usually causes a burnt steel weld?
20. Describe fully how a broken automobile frame can be welded
and re-enforced to make it stronger than originally.
LECTURE NUMBER ELEVEN f
Subject STEEL WELDING
21. (a) What kind of a "filler-rod" is used in welamg cast steel?
(b) Is a flux used?
22. (a) What kind of a "filler-rod" is employed when welding cast
iron to steel?
(b) What kind of a flux is used?
23. (a) Can springs be successfully welded?
(b) State reasons.
24. (a) Why are crank-shaft welds so hard to execute successfully?
(b) What kind of a "filler-rod" is used for best results on most
(c) What points does the welder consider when deciding whether a
weld of this nature is advisable?
25. (a) Briefly describe the method of building up crank-shaft bear-
ings that have been worn down.
(b) What are some of the precautions taken in work of this kind?
26. (a) When automobile propeller shafts and rear axles break, it is
generally adjoining the square end. Is it advisiable to weld this short
(b) What is the correct procedure in a case of this kind?
27. (a) If a case-hardened ring-gear is to have its teeth built up or
new ones added, how is it handled after welding?
(b) Should all case-hardened work be so treated after welding?
28. (a) In welding two pieces of metal, one of which is considerably
lighter than the other, how is the flame held in order to bring both pieces
to a fusion at the same time?
29. (a) If a steel weld were to break in the line of weld, how should it
be prepared if it is to be rewelded?
(b) Does this procedure apply only to steel?
30. Were a hole 6 inches square in a sheet of steel to be welded up
without preheating, what would be the approximate size of the patch
necessary and how would it be prepared, in order to take care of the expan-
sion and contraction strains?
LECTURE NUMBER TWELVE
Subject STEEL WELDING
li. (a) Why should a steel weld of any kind be executed as rapidly
(b} What will happen if steel is kept in a heated condition too long?
(c) Why should a change be in evidence under these conditions?
32. (a) Explain what is meant by a "dished" patch, for boiler or
thin armor plate?
(b) Draw such a patch.
(c) How is a patch of this nature prepared?
33. (a) What is meant by a "corrugated" patch for boiler or thin
(b} Sketch such a patch.
(c) How is this kind of a patch prepared?
34. (a) What advantages has a "corrugated" patch over one that is
(b) Where are "corrugated" patches used extensively?
35. (a) How are boiler flues prepared for re-tipping?
(b) Sketch a simple jig for holding such pieces in place for welding.
36. (a) Describe how lengths of various sized pipe can be welded
together end to end.
(b) What precautions are necessary when executing such welds?
37. (a) When welding large steel castings why is it almost always
advisable to preheat the work?
(&) Why is preheating so necessary on vanadium and other alloyed
38. Why is it desirable to chip out the sand and thin scale formations,
in and around blow-holes in steel castings before filling in?
39. (a) Why do the majority of good welders bend their steel "filler-
rods" at right angles about 6 inches from the end?
(b) Why isn't this being done on cast iron?
40. (a) What advantage is there in making a vertical weld from the
top down, rather than starting from the bottom and working up?
(b) In welding overhead why is it so important that the work be in a
molten state before adding the "filler-rod"?
(c) In overhead welding, why doesn't the metal drop when in a molten
LECTURE NUMBER THIRTEEN
Subject OXY-ACETYLENE CUTTING
1. Explain fully which parts of an oxy-acetylene cutting plant are
different from a welding unit.
2. (a) If there is a difference in either of the regulators, mention
which one it is.
(b} What is the difference?
(c) Why is it necessary?
3. (a) Is it possible to weld with a cutting torch?
(b) What precaution is necessary if this is done?
(c) Why isn't this process used?
4> Explain how cutting can be done with the welding torch if neces-
5. (a) In cutting by the oxy-acetylene process, which does the
cutting, the oxygen jet or the neutral flame?
(6) What action has the oxygen jet on the metal?
(c} What part does the neutral flame play in cutting?
6. Can oxygen or acetylene under sufficient pressure be made to cut .
individually? Explain fully.
7. Why is it specially important that armored hose be used on the
oxygen line when making heavy cuts?
(Give at least two reasons.)
8. (a) How is a cutting torch lighted? Describe in detail.
(b} How is cut started on metal?
(c) How is torch held in regard to metal being cut?
9. (a) Is it possible to successfully cut cast iron?
(b) Wrought iron?
(c) Cast steel?
(d) Rolled steel?
10. (a) Cutting can be done under water with ordinary cutting appa-
ratus; why doesn't the flame go out when submerged?
(b) What additional equipment is generally used in underwater
LECTURE NUMBER FOURTEEN
Subject BRASS WELDING
1. Explain as fully as possible the chief characteristics of a good
"filler-rod" for brass welding.
2. (a) Is a flux used in welding brass?
(b) What is one way of making a good flux for brass?
3. (a) What kind of a flame is used in brass welding?
4. (a) In what position is the flame held in welding brass?
(b} How should the "filler-rod" be held?
5. (a) Is it advisable to " V" out or burn off the ends of brass work to
(b) Explain why.
6. (a) What causes the dense white fumes to appear when fusing
(b) What is cause of brass welds being porous?
7. Why should brass work not be disturbed when red hot?
8. What is the most difficult part of brass welding as a whole?
9. Why are brass welds generally cooled in water as soon as fusion is
10. Why is it difficult for the beginner to weld heavy pieces of
LECTURE NUMBER FIFTEEN
Subject WELDING OF MALLEABLE IRON
1. (a) Can malleable iron be successfully welded?
(b) What is the most successful method of joining two pieces of malle-
2. What are three methods of detecting malleable iron?
3. (a) What kind of "filler-rod" is used on malleable iron?
(b) Are " filler-rods " of malleable iron satisfactory?
(c) What kind of flux is used on malleable iron work?
4. (a) How is a malleable iron casting prepared for welding?
(b) How hot should work be, previous to adding "filler-rod"?
(c) What will occur if too much heat is applied?
5. (a) In what respect does the adjustment of the flame differ on
malleable iron from that of cast iron and steel?
(b) How is the flame held in relation to the work?
(c) Does the flame come in direct contact with the "filler-rod"?
6. (a) Is more, or less, surface covered by the "filler-rod" on malle-
able iron than on cast iron?
7. (a) How should malleable iron be cooled?
(b) Is this the same as in welding brass?
8. On what part of machinery does a welder generally expect to find
malleable iron castings?
9. Explain carefully how a malleable iron automobile, axle or trans-
mission, housing that has been cracked or broken, can be re-enforced
so that it will be stronger than ever.
10. Describe very briefly how malleable iron is made and in what
respect it differs from cast iron when cold, and also when under the influ-
ence of the oxy-acetylene flame.
LECTURE NUMBER SIXTEEN
Subject CARBON BURNING
1. (a) Explain what is meant by carbon burning.
(b) In what respect is it used extensively?
2. (a) Will oxygen gas burn alone or does it merely aid combustion?
(b) Will carbon in a free state burn?
3. (a) Why is it advisable to remove only the spark plugs and not
the entire valve cap or "bonnet" when burning carbon in a gas
(b) Can it be done either way?
4. (a) Does it make a difference if the carbon is hard and dry in the
(b) What will help in such cases?
5. (a) If the cylinder is rather oily does this make a difference?
(b) Does the presence of oil aid or retard combustion?
6. (a) What precautions are necessary before carbon burning is
(b) How is asbestos paper used in carbon burning?
(c) Name a good substitute for asbestos paper when carbon burning.
7. (a) Is there any danger of warping the valves and overheating the
cylinder and piston when burning carbon?
(b) What is the effect of carbon burning on aluminum pistons?
8. (a) What pressure is used on the oxygen line for carbon burning?
(b) Will carbon burning re-grind valves?
9. (a) How long should the burning be done?
(b) How often is carbon burning recommended for a gas engine?
(c) If there are any carbon particles or sand left in the cylinder after
burning is done how are they removed?
10. Describe how the carbon is removed from a four-cylinder engine,
paying particular attention to details such as lighting, which part of the
head the torch is played on first, what does the burning and where the
LECTURE NUMBER SEVENTEEN
Subject PREHEATING AGENCIES
1. (a) What is meant by preheating as applied to the oxy-acetylene
(b} What are several fuels which can be used very successfully for
2. Name the three principal reasons why parts to be welded are gen-
3. (a) Why is charcoal considered the best preheating agent for gen-
(b} Why should it not be used to any great extent in closed rooms dur-
ing the winter months?
(c) If used during the winter what precautions are observed?
4. (a) Mention two materials which are used extensively for building
up ovens and doing the preheating.
(b) What kind of brick is used?
5. (a) How much should cast iron be preheated?
(b) Brass or bronze?
6. Sketch and describe how a temporary brick preheating oven should
be built, giving all dimensions, such as: length, width and height and
reasons for them.
7. Explain how a cylinder block with a broken water jacket is set
up for preheating; how oven is built for charcoal fire; how fire is started ;
how block is protected while welding and how it is returned to a cold
8. (a) What precautions are necessary in setting up and preheating
(b) If piece is to be turned while in the fire, what provision is made in
building up oven?
9. In which cases is preheating absolutely necessary in order to make
a satisfactory weld?
10. (a) Give a sketch showing a preheating torch for use on illuminat-
ing gas and compressed air, which can be constructed very easily.
(b) Why are preheating torches not popular for general welding?
(c) Where are they used in numbers?
LECTURE NUMBER EIGHTEEN
Subject ALUMINUM WELDING
1. (a) Is the welding of aluminum, more or less difficult than such
metals as cast iron and steel?
(b) Explain why.
2. (a) Name the two methods of making aluminum welds.
(b) Can they be combined?
3. (a) What kind of a "filler-rod" is used in welding aluminum?
(b) Is a flux used? Why?
4. (a) Is a cast or drawn " filler-rod " preferred?
(b) Name the two important metals which should be present and the
percentage of each in the "filler-rod."
5. (a) How should the flame be adjusted for aluminum welding?
(b) How is the flame held in relation to the work?
6. (a) How is the "filler-rod" added?
(b) In what respect does this differ from all other metals?
(c) Why can this be done?
7. (a) Name the principal characteristics of aluminum with regard
(b} What other metal acts in a similar manner?
8. (a) Is it necessary to "V" out aluminum for the same reasons as
(6) Explain why.
9. (a) Will an aluminum welding be as strong as the original?
(b} Give reasons.
10. (a) What kind of a tool is used to aid in making an aluminum
weld by most welders?
(6) How is such a tool made?
LECTURE NUMBER NINETEEN
Subject ALUMINUM WELDING
11. (a) What kind of files are used to finish aluminum welds?
(b) In what respect do they differ from the ordinary kind?
12. (a) In which hand is the welding torch held in aluminum work?
(b) In which, the "filler-rod'"?
(c) The puddle stick?
13. (a) What materials are used to "back-up" aluminum work for
(b) Describe fully how aluminum is "backed-up" previous to pre-
heating, in order to prevent the collapse of metal while welding.
14. (a) How quick does the heavy coating or aluminum oxide form
on a clean hot piece of aluminum?
(b) Will the metal flow together when this oxide is present?
(c) How is it overcome?
15. (a) Is it advisable to weld aluminum from one side only or from
16. In preheating aluminum with charcoal, what precautions are
taken in setting up; in starting the fire; during the welding operation,
and in cooling the piece?
17. (a) Are preheating torches played directly on aluminum work?
(b) What kind of an oven is used?
1 8. (a) Is it necessary to heat the whole of an aluminum crank-case
if one part has to be preheated?
(b) Give reasons.
19. (a) Are clamps used to hold parts in place on preheated aluminum?
(b) Explain why. t
20. When starting to weld a cold piece of aluminum, the flame is
brought in contact with the work and held there much longer than on a
similar size piece of steel before any apparent change occurs. How is
this accounted for, knowing that aluminum has a much lower melting
point that steel?
LECTURE NUMBER TWENTY
Subject ALUMINUM WELDING
21. Explain fully why it is necessary to employ greater speed
in the welding of aluminum than on any other metal?
22. (a) What is retort cement?
(b} How does it differ from ordinary clay?
(c) For what purpose is it used in aluminum welding?
23. (a) When performing an aluminum weld by the puddle system,
is the welder dependent upon the flame, the "filler-rod" or the puddle
stick, for the fusion of the metal?
(b) Give explanations.
24. (a) What method of welding is used when executing a vertical
weld on aluminum?
(b) Why isn't the other method used?
(c) Is the vertical welding of aluminum to be avoided?
25. (a) Can aluminum welds be made overhead?
(b) Explain why.
26. (a) Is the same method used on aluminum as in cast iron in
welding from the closed end, toward the open?
(b) Is this procedure necessary on preheated work?
27. (a) If a suspension arm, of a "U" type, on an aluminum crank
case were to break about 3 or 4 inches from the body of the case, could it
be welded in place without dismantling the motor?
(b) Explain in detail how such an arm should be welded.
28. Due to the contraction and expansion, it is very difficult to
have the bolt hole, in the end of an aluminum suspension arm that has
been welded, return exactly to its former position. How is this diffi-
culty provided for?
29. (a) Should a section of an aluminum crank case be missing, would
it be advisable to build up a new part with the "filler-rod" or to cast a
new part in a mold and then weld it in?
(b) Under what conditions should the above be done?
30. (a) If it were found that an aluminum crank case after being
welded, had one corner about f-inch lower than the rest of the case and
it had not affected any of the bearings, could it still be reclaimed?
(b) Give procedure.
Absorbent, acetone as an, 26, 31
asbestos as an, 31
charcoal as an, 31
mineral wool as, 81
Acetone as an absorbent, 26, 31
Acetylene cylinders, construction of,
Acetylene gas, temperature of flame
Adapter, types of, 46
Aluminum, backing up in welding, 114
charcoal in welding, 116
contraction and expansion in
clamps, use of in welding, 115
crank cases, welding, 118
filler-rods in welding, 112, 115
flux method of welding, 109, in
oxidation of bright surfaces in
preheating in welding, 1 16, 117
preheating, method of, 52
puddle and flux systems of
welding compared, 1 1 1
puddle method of welding, 109, in
strains, avoiding internal, 118
suspension arm of crank case,
tip used in welding, 109
welding from one side, 1 14
Apparatus, classes of welding, 19
desirability of securing the best,
Apparatus, emery wheel, need of, 41
high-pressure welding, 20
low-pressure welding, 19
medium-pressure welding, 19
metal top table, disadvantages
mixing chambers, 21
oils and grease to be avoided, 37
oxy-acetylene, for cutting, 125
- types of, 24
required in welding, 19-26
replacing lost cross-bar, 46
setting up, manner of, 31, 32
shop equipment, 39, 43
shutting off, procedure in, 35
Apparatus repairs, 44-50
adapters, types of, 46
gauges, operation of, 49
gauges, safety, 47, 48
hose clamps, 45
hose, repairing leaky, 45
leaks, method of locating, 44
leaky threads, repairing, 44
Asbestos as an absorbent, 31
in aluminum welding, 116
paper cover protection, 55
Automobile frame, welding, 91
Automobile, propeller shafts, welding,
Axles, automobile, welding, 95
Blow holes, causes of, 65
Boiler flues retipping, 98, 99
Boiler, "corrugated" patches, 102, 103
"dished" patches in repairs to, 101
"L" patches in repairing, 103
Borax as a brass flux, 107
Brass, alloy of, 106
filler-rod in welding, 106
flux in welding, 107
fumes in welding, 108
Brass welding, 106-108
Bronze for welding purposes, 123
welding malleable iron with, 121
Carbon burning, 135-144
in gasoline engine, 136-139
theory of, 139
Carbonizing flame, 34
Cast iron, welding of, 58-80
blow holes, causes of, 65
charcoal as preheating
combustion head of cyl-
inder, repairing, 78, 79
contraction of metals in,
prevention of, 71
expansion and contrac-
tion of metals, 65-67
filler rod, 61
flux a cleansing agent, 61
flux, manner of applica-
tion of, 62
flux, simple substitute
for, 6 1
gasoline engine cylinder
block, repairing, 75, 76
gear wheel teeth, three
ways of restoring,
hardening parts by use of
carbonizing flame, 74
lugs, welding on cylinder
Cast iron, welding of, methods of
preparations for, 67
procedure in, 63, 64, 67-70
successful weld, criterion
tip, size of, 63
Cast steel, procedure in welding of, 88
Charcoal as an absorbent, 31
as preheating agent, 76
in aluminum welding, 116
Clamps, inadvisable in welding alum-
Contraction and expansion in alum-
inum welding, 116
in preheating, 53
in welding steel, 87
Contraction of metal in welding, pre-
vention of, 71
"Corrugated" patch, method of mak-
ing, 102, 103
Crank cases, aluminum, repairing, 118
Crank shafts, welding methods, 93, 94
Crater, development and removal of,
Cross-bar, replacing lost, 46
Cutting by oxy-acetylene process, 6
Cutting with oxy-acetylene, 125-134
Cutting torch, welding torch and,
Cylinder block, repairing cast-iron
gasoline engine, 75, 76
Cylinder bore, device for polishing,
Cylinders, acetone as absorbent in, 26
Decarbonization of automobile en-
gines, 136, 139
Demand for oxy-acetylene operators,
"Dished" patch in boiler repairs, 101
Emery wheel, value of in welding
Expansion and contraction of metals,
in welding, 87
Explosions, precautions against, 37
Feather flame, 33, 35
Filler rod, 89
in brass welding, 106
in welding malleable iron, 122
metal in, 61
used in aluminum welding, 112
used in welding steel, 82, 91
Fire brick, in aluminum welding, 116
preheating oven of, 54
Flame, carbonizing, 34
feather, 33, 35
neutral 33, 35
torch, cutting under water with,
varieties of, adjustment of, 32, 33
Flashbacks, causes of, 21, 22
prevention of, 22
Flux, application, manner of, 62
in brass welding, 107
office of, 6 1
substitute, a simple and effective,
Gasoline engine, carbon, how to
remove from, 136-139
Gasoline tanks, necessity for caution
in repairing, 103
Gauges, operation of, 49
safety, 47, 48
Gear wheel teeth, three ways of
restoring broken, 71-74
Goggles, eye, 35
Hardening parts through use of car-
bonizing flames, 74
Heat in welding malleable iron, 123
High-pressure regulated, 24
Hose, armored, used on oxygen line,
clamps in reparing, 45
- leaky, 45
" L " patches, 103
Leaks, method of discovering, 44
repairing threads, 44
Low-pressure regulator, 24
Lugs, welding on cylinder block, 80
"Maine," battleship, wreck cut up
with oxy-acetylene gas, 6
Malleable iron, bronze, welding with,
clean surface, necessity of in
heat in welding, 123
melting to be avoided, 121
preheating unusual, 123
steel strips in welding, 1 23
welding, 1 20-1 24
Metals, methods of distinguishing,
Mineral wool as an absorbent, 31
Mixing chamber, 21
Needle valve, regrinding leaky, 26
Neutral flame, 33, 35
Oils and grease, importance of avoid-
ing use of, 37
Operation in oxy-acetylene welding,
Operator, standing position of, re-
lative to work, 32
Overhead welding, 105
Oxidation of bright surfaces in alumi-
Oxidizing flame, 34
Oxy-acetylene, cutting metals with,
flame, varieties of adjustment of,
in airplane construction, 9
in automobile manufacture, 10
in boiler shops, 10
in brass and copper work, 10
in commercial welding, 1 1
in electric railways, 1 1
in foundries, 1 1
in lead burning, 12
in lumber mills, 12
in machine shops, 12
in manufacturing, 12
in mines, 13
in pipe work, 13
in plate welding, 13
in power plants, 13
in railroad work, 13
in rolling mills, 14
in sheet metal manufacture, 15
in shipyards, 15
in the forge shop, 1 1
in tractor industry, 16
lake boats cut apart by, 8
operators, demand for, 17
scrap cut up by, 6
scrap yards, 15
structural steel, 15
torch as fire department tool, 7
torch can be used under water, 8
varied uses of, 9
Oxy-acetylene cutting, 125-134
apparatus for, 1 25
arrangement of oxygen line, 125
cutting torch, extemporizing a,
flame, cutting under water with,
flickering of oxygen jet, 127
high-pressure and low-pressure
regulators compared, 127
hose, armored, in, 133
pressure of acetylene and
steel and cast-iron, 131
torch in preparing steel, 131
torch, cutting and welding com-
torch, using cutting, for welding
Oxy-acetylene welding, apparatus re-
quired in, 19-26
a fusing process, 62
auto-frame repairs, 4
classes of apparatus, 19
containers, seamless, made
through use of, 3
definition of, i
fire-brick table, 39
future of, 1 7
growth of process, 8
locomotive frames, 4
metal-top table, disadvantages
mixing chambers, 21
operation in, 27-38
principle of , 125
repairs through, 3, 5
shop equipment, 39-43
variety of applications of, 3
Oxygen, cylinders, 27
gas, result of too much, 35
office of in combustion, 27
table of different pressures of,
at various temperatures, 29
Preheating, aluminum, 117
asbestos paper for oven, 55
charcoal in, 53
extraction and expansion in, 53
drafts, protecting work from, in, 54
fuels used in, 53
in aluminum work, 116
reasons for, 51
setting up work, 56
torch for, burning city gas, 54
varied heats for different metals, 52
Preheating agencies, 51-57
fire-brick oven, 54
ovens, 55, 56
torch, burning city gas, 54
Propeller shafts, welding automobile,
Puddle method of welding aluminum,
Regulator, care of, 25
construction and action of, 22, 23
types of, 24
Ring gears, building teeth on case-
Retort cement, 42
Sheet steel and iron, welding, 89
Ships, repairs to seized German by
acetylene process, 5
Shop equipment, 39-43
blacksmith forge, 42
carbon rods and blocks, 43
emery wheel, 41
fire-brick table, 39
flux container, 42
retort cement, 42
Sparks, characteristic thrown off by
emery wheel, 59
Spring's, welding, futility of, 92, 93
Steel, automobile frame, welding, 91
automobile axles, welding of, 95
automobile propeller shafts,
boiler flues, retipping, 98, 99
boiler repairs, 99-101
cast, procedure in welding, 88
construction and expansion in
"corrugated" patch, 102, 103
crank-shafts, welding of, 93, 94
craters, formation of, in welding,
"dished" patch in boiler repairs,
filler-rod used in welding, 82
filler- rod to be used in welding, 97
flame control in welding, 81, 82
hard spots, formation of in weld-
heat treatment in welding un-
equal sized pieces, 97
internal strains in welding, 100
" L " patches, 103
metals, methods of distinguishing
in welding, 87
methods of welding, 82-86
outside appearances in welding, 87
overhead welding, 105
sheet, welding, 89
speed required in welding, 97
springs, inadvisability of welding,
susceptibility of when molten, 97
teeth, building up of, 96
vertical welding of, 104
weld, broken, method of repair-
welding, difficulties of, 81, 92
Steel welding, 81-105
Table of different pressures of oxygen
at various temperatures, 29
Tanks inflammable gases, caution to
be used in welding, 103
Teeth, building up of, 96
Temperature of acetylene gas flame, i
Tip, size of in welding, 63
Ventilation, 56, 108
importance of in welding shop, 43
Vertical welding, 104
" V-ing " metal in welding, 63
Welding, aluminum, 100-117
cast iron, procedure, 67-70
malleable iron, 120-124
Welding, methods of distinguishing
between metals, 58
sparks in determining kind of
metals in, 58
Welding of steel, 81-105
broken weld, manner of re-
cast, procedure in, 88
contraction and expansion
crank shafts, 93, 94
craters, formation of in, 88
filler-rod in, 91
hard spots, formation of
heat treatment in unequal
sized pieces, 97
methods of, 82-86
overhead welding, 105
springs, futility of weld-
teeth, building up of, .96
vertical welding, 104
Wiley Special Subject Catalogues
For convenience a list of fhe Wiley Special Subject
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are arranged in groups each catalogue having a key
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and Miscellaneous Apparatus.
8 Astronomy. Meteorology. Explosives. Marine and
Naval Engineering. Military. Miscellaneous Books.
<> General; Algebra; Analytic and Plane Geometry; Calculus;
Trigonometry; Vector Analysis.
lOa General and Unclassified; Foundry Practice; Shop Practice.
lOb Gas Power and Internal Combustion Engines; Heating and
lOc Machine Design and Mechanism; Power Transmission; Steam
Power and Power Plants; Thermodynamics and Heat Power.
12 Medicine. Pharmacy. Medical and Pharmaceutical Chem-
istry. Sanitary Science and Engineering. Bacteriology and
13 General; Assaying; Excavation, Earthwork, Tunneling, Etc.;
Explosives; Geology; Metallurgy; Mineralogy; Prospecting;
14 DAY USE
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